To be 100% honest, I think that those that have a very specific server in mind would be better off by running their own instance, which I also do on Communick but still need to add Firefish to the list.
For the "basic" access, what I'd like to have is only one "single" instance that can "speak" Activity Pub, and then just serve different frontends that can provide the different functionality. This would IMNSHO make more sense because then people could have one single account regardless if they want to do microblogging, share pictures or talk on a forum like Lemmy.