Looks cool. The announcement talk about watching movies in the Overlay's browser. But I tested this new Steam, and according to the Overlay browser's user agent, it's Chrome 85 (actually CEF), almost 3 year old, full of security holes.
As of 2016, CEF's sandboxing was disabled[0], and I think that's still the case.
This is shockingly irresponsible of Valve. Especially with the NSA saying Steam is a popular attack vector. That's not even due to Steam's Windows 7 support, since the latest Chrome to support W7 is Chrome 109.
[0]: https://www.ghacks.net/2016/02/08/steam-uses-insecure-out-of...
