Unsurprisingly, Google's original line of Pixel phones is no longer getting updated. In fact, what's more surprising is that it got updates for this long. The first Android 11 developer preview is out, and it's available for Pixel 2 and up.
According to Google's page for Pixel and Nexus support, the original round of Pixel smartphones weren't guaranteed to get feature updates after October 2018. And then, they still got Android 10 in late 2019, so Google definitely supported these for much longer than it has originally promised to.
The Mountain View firm has been pretty clear that Android 10 will likely be the last update. The lack of a developer preview image for the three and a half year old devices is the final nail in their coffins.
The Pixel, Phone by Google, and Pixel XL were announced on October 4, 2016, and they were the first devices to use Qualcomm's Snapdragon 821 chipsets. It was also Google's first shot at its own hardware; prior to that, third parties worked with Google to make Nexus devices.