I have a few different modes.
Spend half an hour typing a novel and then delete it, normally because I realise I only half-read the question and went off on my own tangent.
Post something, then immediately realise the comment doesn’t actually express what I mean. CANNOT notice this before I post no matter how hard I try. Delete delete. I also chronically edit past comments, as if anyone cares to read my old comments!!
Post the most random/strange/nonsensical/embarrassing things at night when I’m half asleep. Delete the next day and cringe about it for all eternity. Sometimes I just leave them up in an attempt to accept myself as the odd person that I am (hasn’t worked yet)