I’m shy, introverted, and super casual. I almost never play ‘current content’ and haven’t in a long time, pretty much since Legion (I started doing BFA about halfway through that xpac, and started playing Shadowlands ‘as current’ just before the DF pre-patch came out). Most guilds don’t seem much into having just lowbies questing/running old xpac dungeons, never joining guild discord and only occasionally chatting in gchat. As well as taking months long (or more) breaks randomly.
So the vast majority of my characters are in my own guilds, where I can take advantage of the few guild perks still left, and share my mats and items between characters (and conveniently store gold).