Yeah, I understand a lot of people only play campaign, or mostly play the campaigns, but the longevity of RTS games comes from the online/multiplayer component.
I'm fairly sure those 10k concurrent users playing Age of Empires 2HD these days are mostly multiplayer people. I didn't expect most people on era to play rts games for multiplayer. But didn't expect this outcome either.
But why do RTS games, as a genre,
need to have longevity? I don't want most of my video games to have longevity. I want them to provide a great experience and then go away. Most people feel that way about most games; and even the minority of people who want games to be infinitely replayable only have time for one or two infinitely-replayable games at a time.
Nobody demands that other genres need to have "longevity" or a "community" as a matter of course. Nobody demands that of 3rd person action games, say. Can you imagine someone saying "meh, I don't really count Horizon: Zero Dawn because it has no longevity" or "that single player campaign in The Last of Us is fine and all, but the multiplayer is what really matters, of course". They'd be laughed out of the room.
But when it comes to RTSes, there's an ironclad prejudice in the industry that the multiplayer is what really matters, despite the (apparently) overwhelming evidence to the contrary. Even with the new version of Age of Empires 2, they decided to show it off with some vaunted multiplayer match between two people that I guarantee you 98% of AoE fans have never even heard of. Do they seriously think that most people who buy their new remaster are going to try to climb multiplayer ladder on this 20 year old game? Of course not. The vast majority of purchasers will be people with nostalgia for the campaigns and skirmishes. But the perception that it's all about the multiplayer is so strong, and the small number of serious multiplayer players so prominent and vocal, that it doesn't even occur to the marketers to show the new campaigns or just focus on new features and improvements that affect SP as well as MP.
I really want a developer to announce a traditional-style RTS with no competitive multiplayer of any kind, just to prove that it can be done.