Chromecast is not discontinued - it runs Android TV & I run Smart Tube on it. Also a new Chromecast device was released just a couple weeks ago (I have the previous one).
Chromecast the device is discontinued. Chromecast the protocol lives on. Confusingly it was first named Google cast (2013-2016), then renamed "Chromecast" or "Chromecast built in" (most brands just using the first label), but due to the device's retirement this year, google has reverted the protocol name to "Google Cast" https://en.wikipedia.org/wiki/Google_Cast
https://en.wikipedia.org/wiki/Chromecast