Its a very important point that you did not play those games, this means different factions and unique mechanics alone were not enough to get your interest for them.
Counter question, how many new RTS games were declared at least average by gamers? Strategy games are still popular, its just developers are making these days bad Real-Time Strategy Games.
Let’s compare for example a modern Turn Based Strategy game vs Real-Time Strategy Game.
Warhammer 40,000: Gladius - Relics of War TBS from 2018 vs
Warhammer 40,000: Dawn of War III for RTS from 2017
Both games do take place in same universe Warhammer 40K
But the way how games market did receive both games is very different.
Dawn of War and Relic are very well-known franchises and studio. There was zero competition, game was advertised and praised by the press. 3 factions with unique gameplay mechanics.
Died 2 or 3 months after release, received abysmal ratings and got no support or patches, was very quick abandoned. According to players it had very bad story mode and lame gameplay.
In same time Proxy Studios and Gladius are no name franchise/studio, had like almost no advertisement at all. And still managed to prove itself despite having several mayor titles around like Age of Wonders, Endless legend and Civilisation. They did just by gameplay copy /paste Civilisation. Was launched with 4 faction more and received tons of DLCs and patches, has 7 faction unlock now.
Despite some flaws, people are actually liking and praising it.
So how can it be, that we still have AAA Total War, Turn based strategy games and City Builder like Anno. But if it comes to Real time, people do not like it?
My point is, Real-Time Strategy Games developers these days do make fundamental mistakes.