The staff has gotten a little weird, I suppose it might have stemmed from the way it has always been a two-handed weapon, but in 4e was also a 1-handed implement. 5e may have 'simplified' that into it 'just' being a versatile weapon, but that's not actually simpler.
The other issue is that the bar for 'imbalanced' for weapons seems to be strangely exacting. Fighters/Paladins/etc get w/in a few (or 40) DPR of eachother and it's close enough, one class gets a small bonus on some out of combat checks, another gets a dozen rituals, meh, close enough.
But, weapon edges out another similar weapon by half a point and it's intolerable.
Also weird.
That said, since 3e I've felt like some weapons, particularly the quarterstaff, would be well-served to have different 'levels' of proficiency.
Simple-weapon proficiency with a dagger, for instance, maybe shouldn't let you throw it, simple-weapon proficiency with a staff should be OK to bop someone, but maybe not to do the cool quarterstaff moves like Robin Hood fighting Little John, no tripping & TWFing & such. But, with martial proficiency, go ahead, throw the dagger, go into a pugil stick drill with both end of that quarterstaff.
Heck, maybe all the cool/crazy quarterstaff stuff should be a Combat Style, or part of one (Double-weapon style, maybe)?