From https://www.dignited.com/93186/av1-vs-hevc/:

Compared to HEVC, AV1 is still relatively new hence it suffers limited hardware support. Again it is key to note that Intel, AMD, Nvidia, Qualcomm, and most hardware manufacturers already had support for the incumbent HEVC. That means that a hardware accelerated encoder can run HEVC 5x faster than AV1.

And…

A vast majority of devices in the market; phones, TVs, tablets, cameras, browsers, professional-grade applications, etc come with a built-in ability to decode HEVC. Even those coming from the founding fathers of the AV1 codec have added support for HEVC.