>>51221634>So then why bother with it all, when there are a hundred other better revenge killers?No other revenge killer has the universal application Wobbuffet has. Other revenge killers may provide more utility across the course of a match, but none of them can deal with as many threats as effectively as Wobbuffet can. It doesn't care about speed boosts, if you slap a focus sash on it your opponent's damage output doesn't matter either, it can't attempt to stall Wobbuffet out without risking being encored and giving you a free switch in. If you're faced with an offensive threat Wobbuffet can't deal with, it's either a Skill Link mon, or you're fucked no matter what you brought. As a result, it allows you to use much riskier offensive strategies - who cares if your opponent has one of the many mons that your team's composition struggles to deal with, Wobbuffet can handle it no matter what it is, and you can also use Encore to give one of your other pokemon an opportunity to make a bold setup play.
Wobbuffet is far from the best revenge killer or trapper at hand - as you mention yourself, in most cases you could've chose to pick some other appropriate mon for the same result but with far more utility once it's served its purpose. However, it shines in being nearly universally applicable for countering offensive pressure and exploiting defensive pressure, something that very few (if any) other Pokemon can offer the flexibility for. Good teambuilding typically negates the need for blanket answers like this, but if you're running just the right team archetype, Wobbuffet is a significant enabler.