I think the decision of which cross platform technology to use mostly depends on a team's preferred tech stack.

C++ -> QT

C#/.NET -> MAUI/Blazor

JS/Web -> React.Native/Electron

Dart -> Flutter

This is what I think is holding back Flutter -- that it wasn't built on an incumbent technology. Because Dart doesn't have quite the following, it has to evangelize itself a bit more than the other options.