'Pick the data center closest to you' — closest to whom?

'Pick the data center closest to you' — closest to whom?
Heard this week: an EU agency chose a London region and watched their US buyers lag. Word is the right anchor is your audience, not your office — and on some managed platforms the 'region' you pick only sets the origin, while the dashboard, cron and API calls route elsewhere. A source familiar with one host's topology says cross-region control-plane hops added latency nobody attributed to the host. The advice to 'pick the nearest region' optimizes the wrong endpoint.
Watch this: hosts that won't disclose which sub-services share your region are hiding a hop.