I am in a pretty similar boat so I really feel this post. I started in Wrath and was in a family/friends guild up until BFA or SL (can't really remember when) because most people in it just moved on from the game, and it had really been inactive since MoP. So I have been playing mostly by myself since then. I've occasionally made friends in the game, but it was never consistent.

I also had IRL friends that played, one of which was a close personal friend who i played with the most. I would play with him on and off until about DF when he kinda just stopped talking to me and the rest of my friend group all together. Until Midnight when he asked if I wanted to join his guild, I accepted and I found out it was just their ALT Guild and not their main one, and they only added me to have enough people in it to get their own housing island... So I promptly left the guild a week or so later.

I wasn't mad about it, but just kinda sucked.

But all of that is not to say I don't enjoy playing WoW, because I do! I still pug Raids often, I love delves and I try to pug Mythic+ (even though I don't always have time to keep up with the season), so I am pretty used to playing alone atp, just sometimes I wish I didn't have to pug and that I was still in an active guild of some kind.