pretty unpopular opinion i believe, but i loathe them. they feel like installing apps from the windows store, but worse. i use them on steam deck and my laptop, but they often fail to launch with no feedback[^1], won’t accept drag&dropped files, store their dotfiles in weird places, take up much more disc space (and therefore take literally almost 10x as long to download), won’t inherit the theme (i think because plasma stores the gtk theme in a non-standard place), etc. they feel like they’ve been designed to flout what os developers have built up over many decades and are just a struggle to use.
[^1]: on steam deck particularly (so i know it’s not a configuration i’ve screwed up) no flatpaks will launch unless i launch them twice. even after that, there’s a long delay (~1 minute) and then two instances launch. i know this sounds like i should just wait until the first one launches, but that doesn’t work