> These gamers presumably want reviews of what is / isn't worth their time.
They seem to care very little about the opinions and taste of the people producing content for sites like IGN.
> one streamer doesn't have nearly enough time to review all the games that come out. Not even just the AAA titles!
They usually specialize in a genre, and a lot of gamers are interested in a fairly narrow range of genres.
But also, you don't have to know about every game available. "The perfect is the enemy of the good", also with respect to information. The goal is really just to find enough games worth the time/money to keep oneself entertained. Life's too short to worry about whether you might have enjoyed something else more than the game you actually played. (If you can even justify spending time on video games at all....)
> how are gamers making their decisions about what to play next
Metacritic, Steam reviews, the aforementioned streamers, word of mouth in their own communities... probably other ways....