When Google released the original Chromecast back in 2013, we were far from imagining it would be such a hit and continue to receive support for more than six years. However, it seems the company has stopped providing major updates to the product, and is only pushing security patches to the aging dongle.
Although the dongle still works and continues to be officially supported by Google, it's starting to age, and is even losing compatibility with a few features. This makes sense, as the company has already refreshed the device twice, first with a major revamp in 2015, and a minor refresh last year. It also introduced the Ultra in 2016 with support for 4K video.
The finding was originally reported by 9to5Google, which noticed that the original dongle was still based on the one-year-old Chrome 70, while newer models are using Chrome 74. Indeed, it's stuck at v1.36.157768 versus 1.40.156414 for the other Chromecasts.
Google has confirmed it will "continue to update it with bug and security fixes," which further indicates the first-gen Chromecast will only receive minor updates but won't get any new features in the future. However, it doesn't seem the company has any plans to stop supporting it, so there's no reason to throw yours away for now. You might consider getting a new one if you're looking for more advanced features, though, such as better video quality, multi-room audio, and better Wi-Fi connectivity.