AV1 would be ideal to support. It is resource intensive for software, but with M2 MacBook Pros, for example and upcoming iPhone A17 processors, the AV1 decompression and compression codecs could be put in the hardware.

AV1 reputedly is 30% more efficient than HEVC, important for a number of cases, such as more efficient use of bandwidth over cellular. For FaceTime over cellular Apple today uses the HEVC codecs if available on source and destination phones.

In software AV1 is very resource intensive.