I can’t think of any applications written using those (or any other, actually) cross-platform toolkits for Windows, macOS, Linux, iOS, and Android that were even moderately successful in the market. Generally, cross-platform UIs are disliked or hated everywhere; sometimes with the exception that they’re considered decent in their one truly native environment and terrible elsewhere. Qt definitely falls into this group.

Can you suggest a couple examples? I’m no fan of Electron, but I don’t see it as being so easily replaced as you seem to be suggesting.