It's a bit more complicated.
Streamers don't automatically create stars, but it's the pathway to it.
Tom Hanks, Will Smith, Johnny Depp, Denzel Washington, George Clooney and others got their start on TV.
Jenna Ortega, Anja Taylor Joy and Paul Mescal (Normal People was a BBC mini-series, but it got international attention thanks to streaming) are going from streaming hits to movies. However, none of them are on the level of a Keanu Reeves. Yet.
It is a weird era of celebrity. I do agree that the stars, the actors able to get projects on their name rather than IP, are older. Tom Cruise, Brad Pitt and company are sticking around, and not getting replaced.