ObjC is mostly dead, and most Swift devs are not comfortable with C++.

C++ isn't all that much harder or different from Swift to learn. They play fairly well with each other, you can import and call C++ quite easily from Swift.

It is not like switching from a REPL, browser friendly,inferred typed forgiving language like say JavaScript to Rust with the occasionally cryptic compiler, the unforgiving borrow checker and ownership concepts.

Perhaps people are less comfortable with the libraries and SDKs and tooling from the C++ world for app development. I didn't imagine that such a market was worth buying a company for $610M in 2025 when most apps are web based in one way or other.