I know you're getting a lot of pushback here, but you're totally right. Qt (among others) has been a thing in the embedded space for decades, and we've had snappy UIs on sub gigahertz CPUs for decades. I just don't buy that's it's a matter of under specced hardware.

I'd actually buy that it's more a matter of the corporate sausage making machine that turns ok hardware and talented developers with good intentions into an output of barely usable poorly performing crap. Ie: exactly how we end up with something like Spotify.