I don't think the RTS genre died; I think it evolved. Two of the most popular games in the world, League of Legends and DotA2, are RTS games. The Total War franchise keeps on kicking. Auto-battlers like Teamfight Tactics and Mechabellum mix real-time analysis with turn-based decision making.
It's the old school style of RTS that's dying; harvest resources to build units and beat your opponent. But that style of game was perfected with the release of Brood War, and the core mechanics haven't been improved on since.
I have no evangelism for the RTS genre, but I don't consider a MOBA the same as an RTS. MOBAs are only real time strategy in the sense that it's a game you can't pause where you need to think strategically, and coincidentally has a birds eye view just because it was a WC3 mod. I mean, Smite is a third person MOBA. Is that an RTS?
Doesn't mean they are less valid of games, it's just not what I think of. To me, controlling more than one unit is pretty central to what an RTS is. It scratches a certain commander/godlike itch that other games don't. And those things you list (harvesting resources, building units) aren't absolutely critical to the genre. Company of Heroes is considered an RTS by many
Another trait MOBAs share with RTS is that they use click-to-move, despite WASD being used in most real-time action game genres. The other exception being Diablo (which I believe uses CTM because it evolved from a turn-based strategy game).
It's the old school style of RTS that's dying; harvest resources to build units and beat your opponent. But that style of game was perfected with the release of Brood War, and the core mechanics haven't been improved on since.