One of the weirdest experiences of being a General TTRPG Fan is when someone is describing a system I like a lot, and then draws a contrast to dnd 5e that isn't actually accurate.
Example: "Fabula Ultima lets you reflavor your character freely, not like dnd," except that I've seen plenty of reflavoring in dnd communities before i got into other ttrpgs at all. Fabula is pretty well-suited for it, it does compartmentalize character abilities in ways where combat effects don't have corresponding noncombat applications that would lock them into certain fictional archetypes, but the classes do have thematic cores worked into their mechanics, which aren't so easily ignored.
There's a pretty easy explanation here though, it's less about the demands of the system and more about the play culture they've been exposed to (which you can safely assume is non-representative of the total 5e playerbase anyway). but that's not satisfying to me, because what I really want to understand is the rules-system itself! The play culture is absolutely a huge help for getting into a game, staying interested in it, and actually having fun with it, but i'm here for The Text because that's what can actually be the subject of a design process.