Dude. Dwarves not being mages is literally a lore thing. In fact, dwarves used to be so anti magic that magic items not based on theur class or race could outright fail and cursed magic items would likely fail to work on them as well.
Halflings weren't as 'devout' fir many racial/cultural reasons including how theur relationship with the halfling pantheon.
Orcs and tieflings are relevztuvely need to being playable but reasons fir what thry can or cannot makes mostly sensible if you actually knew the lore and history. An orc bard is just breaking the race, the culture, the religion, and what sets them a part from.others. A bard is more than musical instruments. An orc is just not charming in the way a bard is supposed to be nor do would an orc approach magic like a bard would. Orcs and other humanoid 'monsters' tended to be witchdoctors, shamans, and the like.
A lot of this stuff is seeped into the foundation of dnd/from lore.
A lot if it was/is to actually different between the different races so when you played a dwarf the experience gameplay wise was different than playing an elf.
Hell, in basic dnd, dwarves, elves, and halflings didn't even classes. Lmao (I'm glad that got changed personally).
