Depends on your iteration speed, exact needs, and willingness to work on engine development.
Personally, I'm building my turn-based tactical RPG in it, which is absolutely a Big Project, but I'm not planning to release for a year or two, don't need complex 3D features and am devoting half of my effort to engine dev.
For single-player games that aren't very asset-heavy, I would say 3 months or so for UI to stabilize is a safe point to start work.
For games that have complex animation or sound needs, require networking or want to use a ready-to-use physics library, I'd estimate about 2 years from now.
If you're trying to build a game with very-little coding (and want something comparable to Unity or Godot), "a very long time" :)
Source-available for now, we're still sorting out the exact licensing strategy.
The Bevy code itself isn't very impressive at all yet; most of the work at the moment is on improving the engine and solving some of the remaining design challenges.
We're currently blocked on "clone-able entities" (and ideally "indexes"), and I'm working on an RFC for each of those.
Personally, I'm building my turn-based tactical RPG in it, which is absolutely a Big Project, but I'm not planning to release for a year or two, don't need complex 3D features and am devoting half of my effort to engine dev.
For single-player games that aren't very asset-heavy, I would say 3 months or so for UI to stabilize is a safe point to start work.
For games that have complex animation or sound needs, require networking or want to use a ready-to-use physics library, I'd estimate about 2 years from now.
If you're trying to build a game with very-little coding (and want something comparable to Unity or Godot), "a very long time" :)