Punching Glove is only a 10% boost (plus making punching moves non-contact, which is nice but matters significantly less in a metagame with no Zapdos and relatively low Ferrothorn and Volcarona usage). This is a barely noticeable boost, comparable to a Muscle Band. Crabominable has no way of boosting its own Attack, extremely low Speed, and only barely passable bulk, so it either wants as much immediate power as it can get in the form of a Choice Band or Life Orb, or an Assault Vest to patch up its bulk.
That being said, Crabominable honestly isn't very good in inclusive formats. On paper it seems like a scary Trick Room attacker, and it's not really bad per se, it just struggles to justify a team slot over other even scarier Trick Room abusers like Skeledirge, Azumarill, Hatterene, and Iron Hands. I've actually tried to build with Crabominable several times in Gen 7 to no significant success; Crabominable was decent and put in some work most matches, but there was just very little it did that another Trick Room abuser couldn't do better. Gen 9 does have less competition for Trick Room abusers (no Alolan Marowak, Crawdaunt, etc.), and Terastalyzation does patch up Crabominable's terrible defensive typing, but its other flaws are still glaring and there are still plenty of other Trick Room abusers, some of which will make far better use of your Tera slot than Crabominable.