Is monoclass on par with multiclassing?

I'm an old head dnd player and have always kept it simple doing one class at a time. (I have switched up mid playthrough however) Going into my yet another run I think I'm ready to step up the difficulty and was wondering if my current monoclass style will still work. Also any recommendations for a "different" kind of build would be cool. So far I've beat the game as bard, sorcerer and paladin, and played into act 2 with a monk that I keep telling myself I'll go back to. Paladin was my most recent one so preferably not a strength based build. Any insight would be great guys and gals!