mobile players play on mobile because they cannot purchase a console or pc. this is not limited to just little kids. i myself am a pc player, but i know people who are restricted to mobile games. spoiler alert: they're not little kids.
i mean, the players are not that bad, they just usually suck at games that are playable on both mobile and pc not because they are unskilled, but because the controls are trash af
I don't have a decent phone anymore, but when I did have one that expensive I could run PS2 and PSP emulators on it and play it with a controller anyway, so just saying "mobile" doesn't really mean much anymore in that context depending on how you use it.