Yes! Plenty of us are still stuck on mediocre internet connections that have data caps. My cap at home is 5GB/month!

100MB/app is in the range of "I am not going to download it" unless I have a damned good reason to. Doubly so for updates...

If we're talking Python, then I've had great experiences with Kivy.

https://kivy.org/#home

I have used PyQt. I wouldn't suggest that it's a suitable cross-platform toolkit for anything more than the most basic applications.