Quite often, the 80% are supporting the 20%. I know I've spent many days trying to review PRs for someone in "20% mode", and likewise, when I'm in "20% mode", I

Quite often, the 80% are supporting the 20%. I know I've spent many days trying to review PRs for someone in "20% mode", and likewise, when I'm in "20% mode", I can deluge my coworkers with PRs and RFCs and such. It is very true that reading code can often take more time than writing code. Additionally, the "20% mode" person can often miss little details because they are moving fast, and that detail capture work can take a lot of time for very little code change.