You need something else to run your electron app on mobiles. Ok, you take Capacitor, fine. Probably you'll take React (or something else) to manage your state. Great. You still need some UI toolkit. Literally all of them, even the paid ones, are pretty basic and dumb. So, most likely you'll have to make your UIs pretty basic and dumb, or reinvent the world and/or dig through tons of half-baked libraries which deprecate faster than you manage to integrate them.

Modern QT (with QML) has very low amount of the boilerplate, all the 7guis examples can be implemented with 20-80 LoCs and will run on all the platforms, although despite all the modernization efforts, C++ still feels dated and it's nearly impossible to be productive with it. The main issues are: lack of pattern-matching with type deconstruction, lack of ADTs/GADTs, lack of closed hierarchies, lack of exhaustiveness checks, lack of closed type hierarchy (no top/bottom), lack of typeclasses, lack of first-class functions (yes, while there is some syntactic sugar, it's just a sugar, e.g. you can't return two different lambdas depending on the template parameter from one template function).