We can change anything, and if it makes society a better place then we actually have a moral obligation to try
The problem is that "better" in the context of society is usually subjective. We're talking about a form of censorship, for which change in a positive direction is very complicated at best.
Lawmakers in the US want people to think that ISPs taking responsibility for pirates on their network is a change for a "better" society, for example. Or that net neutrality is unfair to businesses and would result in a "better" society if abolished.
The truth is that it's a ploy to gather unprecedented amounts of data on citizens hiding behind a "won't they think of the children" moral take.
The way I look at it is, the more echo chambers you are in and out of, the more complete of a picture you can get as a whole.
Yes, Lemmy is a certain kind of echo chamber. But you can't really be part of an online community these days that doesn't tend toward becoming one.
You just have to diversify to keep the thread. And Lemmy is a very important part of that diversification for me.