Imagining for a second that I had the technical ability to do so. The thought of running a lemmy server and letting random people make accounts sounds scary to me. Especially a "general purpose" one. I would feel responsible for the crappy stuff posted by users. How do people cope with that.
Also would not be able to conduct the "investigations" required to determine if an instance was csam etc. Because that means you have to go and check it out! we can't have a system where every admin is basically required to view CSAM. that's crazy.