Even if it’s a bait and switch, and they spend 100% of the funds on just like, making the engine better, $8m isn’t going to get you to 1/20th of Unity or Unreal. It is an insurmountable niche.
The size and complexity of these engines can be a disadvantage, because not every game needs the features they provide. For some use-cases, it can be easier to work with a simpler engine with fewer abstractions, a smaller API, and a shorter learning-curve.
I'd argue the only significant thing it's lacking, an actual practical concern for indie game development, is a good asset store. Saying Godot is useless because it will never have feature parity with UE5 is, of course, extremely silly and not a practical concern for most games.
Why is this considered a notable achievement?