But something has changed with the algorithms that determine "Best", "Hot", etc.

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My Front Page keeps getting low-karma, low comment posts displaying above posts from the same subreddits with thousands of karma and hundreds of comments.

Reddit, fix your damned algorithms. Low-effort "what do you think about X?" garbage where the OP contributes nothing to the community needs to stop showing up on the Front Page.

No, that just means people have been shadow-banned from the subreddit. Shadow-banning is a tool to keep trolls from realizing they've been banned. Instead of just blocking them from posting, it lets them post, but hides it from everyone else. That way they don't just go and make a new account.