VP9 vs HEVC

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VP9 and HEVC are video compression standards that aim to reduce the file size and bandwidth of 4K videos.
Apple only supports HEVC, while Google only supports VP9.
We used to be able to watch 4K YouTube videos encoded in H264 in ~2016. Google switched to VP9 only for 4K videos, essentially banning 4K videos on Apple Safari and iOS YouTube.
Not only that, macOS devices only got VP9 decoders in MacBook Pro 2019. Technically we could watch 4K+ videos using Chrome on MacBooks, but the videos were decoded on CPUs, using the CPU 400%.
Starting iOS 14, Apple added VP9 support; Google eventually won. Now we can play 4K videos on macOS Safari and iOS YouTube using this. Apple GPU also now supports VP9 decoding.
Similar to USDZ vs glTF