All of them are OK, except mkv is less a file type and more a container. What should be specified is the code for video, which for most things I'd say AV1, but high res movies might not be the most suitable. Throw in opus for the audio track, and you can use mkv, but might as well use webm anyways since it's more clear what's behind it. (though can still be other things)
I'd also add that jxl should be the standard for lossy images. Better than jpg. And you want something other than png for massive images because that quickly gets costly in terms of size due to png being lossless.
PNG support lossless compression through deflation, but there are encoders that can apply a lossy filter to the image to make the compression more effective.
PNG doesn't support lossy compression natively, to be clear.
I do not think it's mentioned there, but I think webp and also it's indirect successor avif afaik, both lack progressive loading which is not optimal for website loading. It's has incremental loading which I think is akin the the old dial up time of loading top to bottom row for row. They proclaim progressive decoding is costly on memory and cpu, but progressive gives the best user experience imo.
Lastly a fringe issue, re-encooding multiple times. The good old reason why jpgs turn into trash over time because people encode instead of save images. Or because sites re-encode when uploading. Jxl wins here. It also is very easy to see why jpg turns into what it does rather quickly.
I also like the idea of incremental loading, even if it's not that relevant anymore. Also, I don't think your example of generation loss is enough as it's just one image, I would like to see multiple randomly picked images passed through the same process but if the results are the same as here or barely anymore loss than the best option for any given image I do think that's a good result to aim for.
The point is 140kbps opus is almost identical to 320kbps mp3 for human so it saves over 50% size for the same quality. Also it's a royalty free format.
opus is higher quality at a much lower bitrate, meaning you can definitely store more songs in the opus format than in 320 mp3.
opus can be constant bit rate or variable bit rate, whichever you prefer at encode time