Lemm.ee has horizontal scaling, and afaik it’s the only lemmy instance to have added it. He has a sticky on meta@lemm.ee that talks about how he’s using a half dozen different servers to split the load, although there’s a few services that can’t be split like image caching, so they just get their own server. I think the changes are being pulled into future updates so hopefully other lemmy instances can start doing the same
Honestly, the fact that apple used usb-c on it’s “pro” iPads but not the regular iPad is all the proof we need that even apple thinks usb-c is better