There's a whole world of custom split keyboard options out there that use switches where it's super easy to buy replacement keycaps. You can get keycaps made of

There's a whole world of custom split keyboard options out there that use switches where it's super easy to buy replacement keycaps. You can get keycaps made of PBT which are long-lasting and have a very high "rub" factor so you shouldn't have to worry about rubbing them raw for a very long time.