Do you take species biology headcanons :D? if so i like to imagine those gradient finger tips some of the characters have are genetically very common in octarians to the point almost every adult octoling has them and are possible yet much less common in inklings (see:frye)

i think that more official turf war tournaments are very particular about what gear is turf-approved and how its worn. hence why we see so many people wear the same stuff in-game. less official/non-branded games and tournaments are a lot more lenient on accessorization and stuff (at the cost of clothes catching, flexibility, things getting lost, etc)