Google has discontinued the Pixel 4a 5G and Pixel 5 smartphones. The US Google Store currently has both devices listed as being sold out with the only supply remaining through other retailers.
https://www.notebookcheck.net/Google-Pixel-5-Pixel-4a-5G-already-end-of-life-following-the-launch-of-the-Pixel-5a-5G.556235.0.html