I agree, that method might work if you are working solo or in a small team - but for organisations the ability to centrally manage and gate this sort of ruleset avoids drift.
You can manage ADRs centrally too, but you'll quickly need a dedicated sub-team / community / tribe / whatever to manage these thing.
It's a good day to work in a monorepo :)
I have been doing this to great effect and it's maybe five lines instructions total.