You are assuming that downvotes are some metric I optimize for.

No, I'm not. I'm assuming that you're using downvotes for what they are. A representation of a communities likes or dislikes of specific content and their agreement with it. The fact that you call it "meaningless" really demonstrates a lot about you and this whole echo chamber thing you keep complaining about. You don't want an echo chamber where everyones going to agree with you, but you ignore everything that you don't agree with? Riiiiiiight.

Most of my issue is not on topics I comment on or how they’re received, but the topics posted on lemmy and how they are engaged. It’s the comments I haven’t made.

Your entire complaint has been that Lemmy is an echo chamber but now you admit that you aren't making comments or making posts about your views and topics that you feel strongly about. Now you say that "it's the comments I haven't made." So then you are the problem you're complaining about. You aren't bothering to put any effort in to demonstrate your views and then are shrugging and saying that it's an echo chamber. Clearly you aren't worried about downvotes because you just said they're worthless and you don't care, so that isn't the reason why you aren't putting in any effort or even trying. And you clearly have no issue in making comments because you do that frequently.

Thanks to that, the only possible conclusion one can reach now is that you don't care about it being "an echo chamber". You're just a troll. We've ruled out it being afraid of downvotes and you not wanting to put in effort. There isn't any other possible conclusion to reach when you keep painting yourself into the corner.

Have fun with that.