[hot_gril]

An in-between is Super Smash Bros Melee, where a lot of tournament-legal ingame tactics rely on bugs. But only ones you can exploit manually with a regular controller, not actual hacking, and also one exploit called Wobbling got banned in 2019 (note that this is a 2001 game).

[vitiral]

In those cases the bugs are more like advanced fighting moves. I don't think item dup or insta-kill bugs would be allowed, even if they did exist.

[hot_gril]

Surprisingly none of those bugs have been found, but yeah they'd be banned. The weirdest thing people actually use is the yoyo glitch, which allows Ness to hit a player with a powerful move from anywhere on the map, but it's hard enough to execute that it's not OP.