Unless there is a serious rewrite, Godot will never be a valid alternative to the two main commercial engines

How so? I've seen complaints about the C# API and some similar challenges, but nothing show-stopping. Obviously you won't be making a AAA game in it, but for indies it looks like a decent option.

The dirty secret of software is that any given user-facing OSS application is about 15 years behind the closed-source competitors, but the fact is that most software was good-enough 15 years ago and the industry has spent the last 15 years on cloudifying and A-B testing and GUI revamping and other stuff that isn't basic functionality.