> This is false, Unity is very popular, I've played several professional games made with it, for example.
This is true. Just look at statistics about which game engines were the most popular on Steam: https://steamdb.info/tech/
It's the most popular game engine out there by far.
Here's the top 10:
Unity 29797
Unreal 7665
GameMaker 3173
RPGMaker 2141
RenPy 1392
XNA 595
Godot 504
Adobe AIR 405
Cocos2d 358
MonoGame 293
>, but surely pro shops are not using unity (on the whole)?
This is false, Unity is very popular, I've played several professional games made with it, for example.
https://en.m.wikipedia.org/wiki/Neo:_The_World_Ends_with_You