I faintly recall an interview with one of the developers not too long ago, maybe a few years ago or so, where they said Sweeney still touches some 80% of the code base.

Also, there's always this old gem that HN should get giddy about: https://www.st.cs.uni-saarland.de/edu/seminare/2005/advanced...

I just think JC/Abrash/etc have an aura/cult of personality that doesn't seem all that impressive when you get someone who is a powerhouse of tech and business acumen like Sweeney next to them.