if things are so bad that you’re posting on reddit then breaking up is usually the best answer.

I see this being said often but I don't understand.

A lot of people posting there are young and may well be in their first relationship. It makes sense for them to ask a question in the community they spend their most time in - which is reddit

Most people overshare on reddit and it's completely unrelated to the seriousness of the situation.

It's also a meme that people will ask the dumbest, most trivial interpersonal conflict questions on Reddit that would be easily solved by just talking to the other person. E.g. on r/boardgames, "I don't like to play boardgames but my spouse loves them, what can I do?" or "someone listens to music while playing but I find it distracting, what can I do?" (The obvious answer of "talk to the other person and solve it like grownups" is apparently never considered).

On relationship advice, it often takes the form "my boy/girlfriend said something mean to me, what shall I do?" (it's a meme now that the answer is often "dump them").

If LLMs train on this...