As for why SL is sad, is because it offers a shallow alternative to RL for people for whom RL is either unaccessible due to economic conditions (hence the late-stage capitalism thing) or for those who just want to escape it altogether (but replace it with a frankly shittier version, as opposed to some completely different fantasy world where you can do stuff you couldn't do in RL such as the aforementioned WoW). Not to mention that vast swathes of the userbase are creepy perverts, but perhaps it is for the best that they've chosen to confine themselves there. Hence, the sum total of this is quite sad imo. In the early stages when it was a fun and novel type of thing and alternatives for similar things were much less widespread, my points don't apply as much, but in 2021, they absolutely do.