Samsung is garbage IMO, and OnePlus has been getting worse for years. Pixels offer the smoothest experience. Nothing phones are really nice too.
Wdym about the gifs? there should be nothing stopping you from sending those on any device.
Sideloading is possible, but there’s more hoops to jump through than on Android. Plus an overall smaller amount of apps available to sideload.
Piracy depends on what you’re pirating. TV/Movie wise you’ll be fine, as well as ROMs for the few emulators iOS has (relative to android). I doubt you’ll have any luck with apps or mobile games.