They compete with each other. Imagine how many indies one of the major consoles would draw by making it so much easier to develop.

The issue is the other way around.

The companies hold the gates to millions and millions of potential buyers. Indies want to sell in all of them and there is no other way for them to do so.

In addition, consider that most indies use Unity/UE, which already support the consoles, so vendors couldn't compete on ease of development even if they wanted.

If Godot was overwhelmingly used by indies, then yes, you could be right.

Most indies already use Unity, which has support for all consoles. Most indies don't even know a single native API call. Unless the game needs something very special, they just use Unity API for everything.