Regarding publishers, none of the ones we pitched CB to (in 2019/2020) seemed to be put off by our decision to use Godot. If they were, they didn't say it. And actually, a few were quite interested in Godot themselves even back then.
Godot is perfect for small projects. For medium/large indie projects, if you're not afraid to get your hands dirty with C++ engine code, 3.x is already good enough! I suspect that Godot 4.x will be in a similar state next year, and continue to improve after that.
One last point to make for (ex-)Unity users: don't overlook GDScript! You're all so laser-focused on C# that you miss one of the best things about Godot!
In GDScript, there's no garbage collector to tiptoe around, the VM uses engine types natively without need of a translation layer, and there's syntactical sugar for common engine tasks like retrieving nodes by path, etc.