Comment by josephg

So? File size matters for delivery formats. But not for intermediate formats straight out of camera. For editing, bitrate and decode performance are often way more important.

Hardware decode support for AV1 and H265 is still pretty bad. If you use those formats, a lot of computers will stutter when you move the play head around while editing. On my mirrorless cameras, I much prefer filming in medium to high bitrate h264. I fill up my storage cards faster, but my camera batteries last longer recording like that and the footage is much easier to work with. I have a 4090, which supports h265 decode. But it only works for 4:2:0 footage. If I film in h265 422, my computer falls back to a software decoder. It's easier to just use h264, then I don't have to think about it.

If you want to ship high quality deliverables, you don't want resolve to do the final encode anyway. Resolve tries to use NVENC for encode, which is a much worse encoder than x264 and friends in ffmpeg. From resolve, output prores or something. Then use ffmpeg to do the final encode. I think there might also be ffmpeg encoding plugins.

tldr; Codec matters, but there's a lot more nuance to getting a good image than just picking the newest video codecs.