Yeah. But horizontal scaling (well horizontal scaling in a system like this where you need clustering so the instances talk to each other) is hard. And I think there are a lot of other things that need to be polished, added and worked on before that. It would probably also need somebody with knowledge of clustering to start contributing. I think step 1 needs to be that the dev team needs more help properly tuning the database use. The database is very inefficient, and they lack the skill to improve it:
We are in desperate need of SQL experts, as my SQL skills are very mediocre. ^https://github.com/LemmyNet/lemmy/issues/2877^
So getting help improving the database is probably the #1 thing that can be done to deal with the scaling problem.