Annoying. Just go see the items held by Gym leaders only in Kanto:
If one Poke has a comp Item is no problem; if two mons have a comp item is no problem; same with three; when all the pokes have comp item, now THAT'S a problem. I'm tired of Brock's "Resist" team either with the ability or the object, I'm tired of Surge's Balloon team, all the Bijoux, I'm tired of fighting mons with Hidden Abilities, which new players don't even know exist, AND I'm sick of fighting against mons with always the right secret power ALL THE TIME. Building a team this way is just a lazy approach. Instead of thinking "which one could be the better set for this mon or gym leader from a tactical standpoint" are built around "just max all out to overspeed or shot apponent's team or just to make the battle longer even if without a possibility for the Gym leader".
Play since 2015, trained countless hours against hordes, never seen a shiny.