Why have some older chess-like games fallen out of popularity?

I've been playing a bit of Shatranj recently. It's a very fun game that plays a lot like modern chess, but has more of a strategic/maneuvering theme to it while keeping most of the tactical elements intact. I rate it a game superior to modern chess, but I can't practically take it very seriously because there aren't too many people to play against.

I understand that it's natural for a game to evolve over time, especially in the context of older societies where instant communication was not a thing. But why would such a quality game not only be drastically altered into a faster game, but be completely pushed out of the scene by said descendant?

This is not a rhetorical question or joke, by the way. I'm genuinely curious.