[aboodman]

Only in the case where there is such a majority of the company that is tightly geolocated.

Again, AWS latency us-west-1 to us-east-1 is 70ms. That's absolute best case for one round-trip that does absolutely no work. And it's ignoring the case of anyone outside of continental US.

Add in actual server-side work, db interactions, and contention - and you're quickly looking at hundreds of ms.

[bastawhiz]

If your users are truly broadly geodistributed, there's no avoiding hundreds of milliseconds of latency if you want strong consistency. You're fighting the speed of light. You can move the source of truth closer to the majority of users with effort without meaningfully regressing performance for the users who aren't tightly geolocated, so you can treat it as a fairly pure optimization.