I can't imagine all that many people are using just Chromium itself though. Most beneficiaries of Chromium are by virtue of browsers built on top of it such as

I can't imagine all that many people are using just Chromium itself though. Most beneficiaries of Chromium are by virtue of browsers built on top of it such as Brave, Vivaldi, and Edge, all of which have already built their own synchronization services. And if someone was using Chromium, I would think there's a decent chance they would switch to one of those three.