The only differece is that Starcraft like Warcraft 3 and C&C got asym factions. Something we get in to Age this time. For the rest those games are not dead neither AoE 1-2.
I still do not get what are you doing here if you consider this a dying genre
Knights and Merchants, Stronghold and others were niche games. Games that are too complex and realistic become niche. None want niche games except a bunch of players. Theres no point to invest resources and money just for a bunch of dreamers. AoE1-2/Starcraft/Warcraft3/C&C:generals are the games that made the story of the genre.