I have been involved in two non-trivial Qt mobile apps. Never again.

I don't know what your experience is, and I mean no offence or anything, but the only people I have seen who were happy with Qt for mobile development were people who had never tried to do it with a modern language, like Kotlin.

With Compose Multiplatform and Kotlin Multiplatform, you can write a cross-platform app in a modern language, and that is far better than C++.