You are posting this on lemmy.world with your lemmy.world account. Perhaps you can start by migrating yourself to another instance?
Every instance has different resources (hardware, people, time). Some instances are able to support more users while some others are intended for small audiences.
I don’t know the architecture of Lemmy, but in many cases a server can be scaled for more users, by load balancing, distributed computing etc.
Agree with you about karma, but downvote might be necessary in order to keep spam/trolls/self-promotion etc away.