The gathering would absolutely dominate the game. You'd have to run through the mage's scavenger hunt for components before you actually got to anything good. Or you could make it prohibitive, but then the mage feels bad because not only are they limited by, say, the Vancian system, but oh, yeah, whatever spell they cast just has a component you can't find here so you have to do something else.if 95% of the time they weren't just immediately waived away by having a component pouch or arcane focus/holy symbol would needing to aquire the right material components for spells be categorised as resource management? have any of you played a campaign like that where you actually have to first aquire the piece of cured leather for mage armour, or the lightning-struck twig to cast witch bolt?
Even if the players overcome it, it would just end up being "i gather enough to cast a spell some arbitrary amount of times" and be done with it, which isn't much different from handwaving.
It might be interesting if there was just one player, but with a party, it'd be pulling teeth, like having the fighter have to roleplay out the care for their weapons and armor.