I really don't think anything has fundamentally changed with the community or platform since the decision to remove downvotes in the first place. I just don't think the population of Lemmy as a whole is large enough or mature enough to use them in a responsible manner and it will continue to be used as a "this isn't my fetish" button rather than any indication of quality or community relevance just like before.

I agree that the spam problem has gotten worse over time, but I really don't see downvotes doing very much to fix that. Most of it is from content sellers. They only need one post to do well to get their visibility and they almost always get at least that much so they still end up rewarded for the behavior in the end.