I think it's more likely that they just make money off of their client via Nitro and other random features. Having other clients would let people get around tha

I think it's more likely that they just make money off of their client via Nitro and other random features. Having other clients would let people get around that while still using Discord's servers/bandwidth. And there's definitely technical issues with supporting other clients. Can make it hard to change things without breaking those other clients.