Does everyone always have to be involved in everything? Of course not.
The Thief goes off and scouts - and does a little quiet pilferin' in the process.
The Magic-User blows up what needs blowing up.
The Fighter chops down what needs chopping down.
The Cleric bats cleanup while providing support and cover.
Sometimes things don't need blowing up. Sometimes there's no scouting to do. Sometimes there's nothing to swing a sword at. And sometimes the Cleric is a 5th wheel.
Know what? As long as "sometimes" never becomes "all the time" there is no issue.
Lan-"sometimes you just gotta sit back and enjoy the ride"-efan
Yeah, classes are there to fill roles. I'll never understand this one character has to do everything attitude, or that all classes has to be the same.
See, this just gives me flashbacks to pre-4e Shadowrun where everyone would go out for pizza while the GM had his hour and a half one-on-one session with the Decker.
It wasn't fun.
It wasn't fun for anyone.
Also, Magic-Users stopped being "guy who blows things up" long, long ago. They've been "Guy who has a spell for goddamn every single little thing" for awhile now. That's the problem with Vancian - you change your spells every morning. You can specialize in "being specialized in anything"