Can you point me to one of these subs you are talking about?
/r/askengineers
/r/SEUT
Lots of the fiction and story subreddits, /r/maliciouscompliance is hilarious.
There are multitudes of art and music subreddits, choose your favorite genres.
/r/neutralpolitics is a great heavily moderated subreddit that requires HQ citations for any statements of fact posted.
The diet and fitness subreddits are super supportive and positive.
Tons of artists have their own subreddits, e.g. Swordscomic got its start on Reddit, and still has a really active subreddit.
It's the old question of liking something despite knowing it's (probably) fake: Usually it doesn't hurt, and can in fact mean that literally nobody got hurt.
But there's a general tendency of such content attracting hatred: If it does not explicitly identify itself as fictional, people don't like the idea of it being believed to be true.