You killed the vibe in this comment chain for starters. The phrase “F” is one of, if not, the simplest ways for expressing empathy, as opposed to an attempt to be funny. It also serves its purpose as a throwaway comment for a post that explains itself and needs little to no feedback yet receives it anyway. I will agree with you that it may be “overused to hell” and “isn’t fucking funny”, it does in fact have a valid purpose than just to bother.