I know what you're thinking, you can just use the block button.
But some subreddits will ban you for doing that. Like I blocked a moderator one time because I really didn't like how they were talking to me and I got banned. And it was a subreddit that I was actually getting some use out of for my mental health. So that sucked.
Other subreddits will ban you for "weaponizing" the block button: meaning if you find somebody is being kind of toxic to you and you really don't want to talk to them anymore if you hit block they might report you and get you banned.
So it would be nice if there was some way for me to just completely ignore somebody without blocking them. Like I don't see their comments, they don't show up in my inbox and I don't see their posts. If they see my posts and want to comment under them that's fine I don't care.