i also use arch and firefox/mullvad browser do take a lot longer to launch than normal. my problem could be some dependency missing (ive already got problems with video codecs i have no idea how to fix) or a broken swap partition. So, does reinstalling firefox help? and do you have a swap part? if yes, how big did yoy make it?
most stuff on playstore works on all devices, so thats probably why you never saw one. i only discovered th`t because i had(and still have) a phone thats way older than most people's
if you generally buy newer phones its harder to find unavailable apps
i always use software for what it is, ignoring the beliefs of its creator, but ive already been using firefox, librewolf and mullvad browser since i moved to linux, and i have only been seeing people say stuff that shows chromium is worse. (except for people with no argument of course)
yeah bring back the infinitely long knife