Except for some odd corner cases, it is very hard for a good engineer to beat compilers these days (they are very good now). Not to mention, tuning depends on the platform, and often the exact model of chip.
there were two lead developers from FFMPEG on Lex Fridman's youtube channel who talked about performance gain from assembly. They claimed the opposite
* it is very hard for a good engineer to beat compilers these days (they are very good now).*
I keep hearing this for the last 20 odd years, yet I see evidence to the contrary each and every day. It is hard and honest work though.