I don't think this comparison makes sense - HEVC and HEIF are both industry standards, and will probably see widespread adoption. HEVC (H.265) is already really

I don't think this comparison makes sense - HEVC and HEIF are both industry standards, and will probably see widespread adoption. HEVC (H.265) is already really taking off, especially now most modern Intel CPUs have hardware support for it. Their main predecessor technologies, JPEG and H.264, weren't 'open' formats either. In the case of HEIF, MacOS/iOS will automatically transcode to JPEG anytime you share a HEIF image - it's solely being used to save storage space on your personal device, so in reality almost no one will even notice the change, save for the upside of having more free disk space. H.265/HEVC is pretty trivial to transcode to H.264 or whatever else you want, but given how wide support is spreading I doubt people will often have to do this. Metal on the other hand is an entirely Apple in-house technology.