>>41411459It's not very fast and has an awful defensive typing. The high defenses aren't as good as they first seem because it has low HP, and since it's weak to so many common types it still can't take hits well.
Offensively it isn't very good either. Even ignoring the lack of speed, it's offensive stats are weak, and it's movepool in general is terrible, all it has is Psychic and Bug STAB plus Shadow Ball. Bug moves are nice for countering Dark types and opposing Psychics, but pretty much every other Psychic type can already do that with Focus Blast and Shadow Ball. Unlike other Psychics with access to Focus Blast, Orbeetle is completely walled by Steel types.
Sure it can set up Screens but so can pretty much every other Psychic type and tons of other Pokemon, even just from gen 8 Grimmsnarl uses screens better and it's dead weight otherwise. Hell, even Dottler does it better since at least it can use Eviolite to supplement its bulk, it's not like the lack of offensive stats matters for something as weak as Orbeetle.