I'm pretty sure a majority of Pokémon fans were introduced to the series via the anime. I remember waking up early in the morning every Saturday to watch a new episode of Pokémon when I was younger (and still today occasionally), you get the same story from a lot of fans here too.
I'd also like to mention out of the whole franchise, the anime is probably the most popular behind the games.
But yeah, like I mentioned, the anime plays a big role in helping the franchise and advertising for the games. The anime could go in a completely different direct route dissimilar to the games story wise, but it doesn't mainly because it probably will get game audiences, and bring in audiences to play the games. That makes sense right?
Despite this communities unpopularity of the anime section, places like Bulbagarden and Serebii forum's anime sections are the most popular, for their own reasons of course, but still shows the show is still alive and popular today.