I think the reason is that the versioning tooling is 1% of the work, so making it 0.5% would not be "twice as effective", it would move from 100% to 99.5% work

I think the reason is that the versioning tooling is 1% of the work, so making it 0.5% would not be "twice as effective", it would move from 100% to 99.5% work to be an openbsd dev. Diffs mailed between devs still look the same, oks for diffs are still a social construct that needs persons and not programs.