Reddit was enshitified circa 2014 or 2015, this is not a new thing. It's been garbage for a long time and I'm surprised it's taken so many this long to notice. In fairness if you kept to subreddits that were eminently unpopular and off the beaten path then it wasn't as obvious.

I guess the mobile app was what really broke the camels back but the quality of the posts had been on a downward trend in a severe way since at least Obama's second term, when I think both political parties recognized it as important and began to manipulate it. This is made easier by the partitioning of the site into subreddits. I hopefully don't have to explain here why that makes automated sockpuppeting much more effective and easier to accomplish. It's a fundamental design flaw (if we were to assume the design of Reddit was intended at all to provide a space for authentic personal takes on real issues and by real humans).

There is a danger of the same thing happening to HackerNews but I hope the lack of financial incentives to allow that sort of thing does some work to mitigate it, along with the lack of partitioning of the community.