Three artefacts fix most of it. A style guide, so decisions about voice and terminology get made once. A set of templates, so the shape of a runbook or an ADR is not renegotiated each time. A short list of standard operating procedures for the things that must not be improvised, like release and incident response.
That is the whole system. It is small on purpose. A style guide nobody reads is worse than none, so keep it to the decisions that actually recur: product naming, capitalisation, how you refer to the user, how you format commands.
The payoff is not tidiness. It is that a page can be written by whoever is closest to the work, and still read like it belongs. It is that onboarding stops depending on one person's availability.
Treat it like infrastructure. Own it, version it, and budget time for it, or it decays exactly like anything else you do not maintain.