The Chromecast is a simple device that does exactly one thing and does it well. Six years after its debut in 2013, the original Chromecast is still useful, even after the Chromecast Audio came and went, and the introduction of the more powerful Chromecast Ultra.
The first generation of the device may no longer receive feature updates, however. As noted by 9to5Google, on the Chromecast support page you can see the firmware available for each version of the device, in both current and preview versions. While recent generations support firmware 1.42.168007 and above in the preview version, the first generation Chromecast is still on firmware 1.36.159268.
This suggests that the first-generation Chromecast won't won't get the same amount of attention as Google's other streaming devices in the future, although the company has not confirmed whether it is ending support for the device. In a statement to 9to5Google, Google said it will "continue to update [Chromecast] with bug and security fixes."