I have been afraid to use Unity ever since they acquired IronSource, a company that has been known for adware. However, I tried Unreal Engine and there were issues with scaling when using the Blender models and MakeHuman characters, and Unity doesn't have such issues. Is Unity still a safe engine or should I try something else?

What are your fears?

They acquired a lot of companies for a lot of technology, including allowing developers to incorporate ads into their products. You can choose to include ads, or not, at your own decision. All software includes risks, bugs, and flaws. It's considered safe enough for game studios around the globe, both large and small.

If you have some specific fear or a specific risk then somebody might know. But a general “is it safe” I'd say it has always been safe. It's not like IT departments at major companies like Microsoft or EA demanded it be quarantined or anything.

I think Windows blacklists IronSource. Also, many people thought Unity was going to die out because of all this.

BradleyAuerbach said:
I have been afraid to use Unity ever since they acquired IronSource, a company that has been known for adware.

What are you worried about? That they would suddenly force you to add ads to your game?
If it were the other way around (Unity acquired from Ads company), this might be eventually their intent, but even then i doubt existing agreement and license terms with users would be affected.
In the worst case you could just stop updating, so not accepting future changes in terms to be safe from that.
I'm no lawyer, and don't know Unitys terms, but i would not be worried.

Think of such worst case, e.g. Unity asking for money to be adds free. This would only make more users switching to competitors like UE, so they would shoot their own feet.
Rather i guess it might just become easier for devs to include adds into F2P games if the devs want so. So benefit for all parties. New options, no enforcement.

I would be much more worried about having only a tiny fraction of the source code from the game i work on, if at all ; )

@JoeJ Also, one of the developers said you won't be able to make a living off of game development without using IronSource I think. They even insulted those who don't use it or similar tools using a bad word.

BradleyAuerbach said:

@JoeJ Also, one of the developers said you won't be able to make a living off of game development without using IronSource I think. They even insulted those who don't use it or similar tools using a bad word.

You'd need to post links to such claims so people can see the sources to comment on them.

Not knowing anything about that, i can only say: It's 2022. According to somebody, everybody is an idiot. Epic games Launcher contains spyware so China can read our minds. Earth is actually flat. James Webb Telescope confirmed aliens. Musk is an AI bot sent from the future.
Choose the truth you prefer, or accept uncertainty is our only true option.

So are those your fears?

BradleyAuerbach said:
I think Windows blacklists IronSource

Is that your fear? Misquote that was spread. IronSource is a tool, and many people including malware creators used the tool. The malware was banned, not IronSource. Similarly, Visual Studio is used to create malware, and that malware is banned, not Visual Studio. Python has been used to create malware, and that malware was banned, not python. Email scripts have been used to create malware, and those malware scripts were banned, not email.

BradleyAuerbach said:
many people thought Unity was going to die out because of all this.

Is that your fear? Unlikely, but sure, it's possible that a corporate misstep can end the company. Unity is worth 11 billion dollars, is publicly traded, and used by studios around the globe for many products, including many major games. It is possible that the acquisition could sink the company, but highly unlikely. If you're trying to manage risk of using Unity versus the risk of using other engines like Unreal, CryEngine, Godot, Torque, jMonkey, or any other tools, that acquisition wouldn't even appear on my personal risk radar but it might be something that somebody might be concerned about.

BradleyAuerbach said:
one of the developers said you won't be able to make a living off of game development without using IronSource I think.

Is that your fear? That's laughable, and doesn't pass a basic thought test.

Consider the huge range of programs that use Unity. They're going to force it onto Hearthstone? Force it into Cuphead, into Rust, into Untitled Goose Games? Force it onto all the platforms, the games that ship on Xbox, Playstation, or Switch? Or maybe they'd be forcing it into the editor? Somehow thousands of game studios, everyone including fortune 500 companies will be required to enable it through their sometimes strict network policies?

However, making it available to developers who want to include it, that's far more likely, and in line with what they've done on many acquisitions. With that, developers who want to include additional technology will have the option to include it, those who don't can choose that.

BradleyAuerbach said:
They even insulted those who don't use it or similar tools using a bad word.

Is that your fear? Somebody somewhere insulted someone, so the using the tool makes you ${badword}? I'm not sure how that equates to a fear, but if you're concerned about what some stranger online thinks about you, you'll need a far thicker skin to enter industry. Not just the game industry, but honestly, any industry. It's a cutthroat world out there, and plenty of people will happily rip you to shreds, some will do it just to get their own gain, some will do it for their own perverse pleasures or because they're bored on a Tuesday.

@JoeJ OK then! And people tend to be VERY negative on the Internet! Just look at the Minecraft community and content creators for that game right now! A lot of them are so upset about recent updates that they think the whole game is going downhill!

BradleyAuerbach said:
look at the Minecraft community and content creators for that game right now! A lot of them are so upset about recent updates that they think the whole game is going downhill!

140 million active players globally and 13 years of play? Yes, the entire industry has been waiting for Minecraft to eventually start to level out rather than continue what started as a meteoric rise, and has been the biggest industry player for about a decade. If it's going down, it's about time!

BradleyAuerbach said:
@JoeJ OK then! And people tend to be VERY negative on the Internet! Just look at the Minecraft community and content creators for that game right now! A lot of them are so upset about recent updates that they think the whole game is going downhill!

Sure. Whole world is going downhill, so what do you expect? We just have to deal with that.

I think you got the answers you asked for, but i really think you are a victim of modern times.
Think for yourself, judge yourself, grow a thicker skin, don't censorship yourself (replacing ‘idiots’ with ‘bad word’ - just to be conformal to observed correctness?).

Occasionally, some days ago i came across this video.
I did not know about this game, and how accurately it predicted the future. Turning it into a science fiction masterpiece in line with works like 1984. :D
Hats off to that. Probably that's all we can do about it, being just game developers.