Well boring/vanilla is a matter of taste. It’s not a bad thing, gives newer players a class they can join in with even when 0/8, and I like going assassin if I’m wanting casual play (press space get paid). There’s always going to be one class at the bottom of the list, for some it’s assassin, others priest/sorcerer, or necro, even pala can be boring if you prefer the action of warrior/knight.
I can’t tell if you are serious, or maybe misunderstanding what I’m describing - have you not played assassin much in a small group or solo? Because in almost every “threatening” location assassin has option to do this. Apart from those where we get locked in without somewhere to run to:
Assassin can do rages like Daichi, Janus, and Tombs without even stepping anywhere near the bosses, in Lod can solo Ivory rage with poison. All the serious realm quests - including Sentry, just run in while Sentinel is round the other side and spam, run back out. I fought most of the Biffs in Motmg with assassin to guarantee SB with zero need to risk him standing on me like I’d need to on a melee. If unmaxed/low pet you might do it in places like Malphas or Limon, even Stheno and hell the Jungle boss too. I’m gonna stop but hopefully you get the idea.