That's just growing pains from a sudden mass migration, the hug of death if you would.
User base growing organically over time will make this happen less and less.
Lemmy as a software will get more sophisticated, the people running the software will get more used to how things operate and be able to buy more/better hardware, etc..
Right now things are just a bit chaotic from thousands of people jumping ship at the same time.
Dwarf Fortress isn't a colony sim game, though
It's a tavern corpse clean up sim.