Projects that use ty for its type checking but something else than uv for managing dependencies are probably in a very tiny minority of users.
Ty's original pitch was that it would have strong inference and be useful for gradually typing existing, untyped codebases, but AI made that moot. Adding types to existing code is now trivial.
Not sure if that's true.
Use whatever tools you want, but don't kid yourself. There's a reason Google adopted Pyrefly.