All big projects have open GitHub issues. You just linked to 500 open and 3000 closed bugs in V.
For example, Rust has 8000 open/35000 closed. Yet it's a very mature language.
V is very stable for its age. The compiler can build itself since the release (it now has 220k lines of V!) and we have big projects like the Vinix OS written entirely in V, and it can already run GCC/g++ and Doom for example.