Well first A20 Pro didn't get wider, it actually shrink back to 9 decode width. It would be a lot better to compare it on the A silicon rather than M.

Second is that Apple's improvement were done when they were state of the art and leading the pack. This is a lot harder than when you are behind and being shown how much more room to grow.

The A20 Pro is the largest leap in performance in recent or perhaps in all of Apple SoC history. It doesn't get enough credit and attentions that it deserves.

Compared this to the article "How did AMD Ryzen get 50% faster in two years?" The Zen 3 uArch being used in the article came out in 2020. So it is more like AMD got 50% faster in 5 years.

And perhaps this also answer and refer back to the previous HN submission and comments as to why ARM Mac are slower on SVT-AV1 encoding. Apple's SIMD performance is still behind AVX-512. But it is for good reason though and the trade off IMO is well worth it.