I would assume people would capitalize their titles in posts since that’s the standard pretty much anywhere else like on YouTube or news sites, and that’s what you learn to do in school. Why is it only different on forum platforms like Lemmy or Reddit?
A real title, one that you would typically capitalize the first letter of each word, does not have to be a sentence and often isn’t. But many “titles” on forums like this are really sentences which capture the whole essence of what’s being asked or stated, like your “title” does. As I browsed my “front page” (for lack of a better term) just now, indeed I found that titles followed that rule.
Oh, so they’re basically just summary lines instead of titles?
Exactly. Often the title is longer than the text of the post, and may even just say “title”.