It’s pretty common for people to have a “work” computer and a “home” computer.

And also most of android population use chrome.

And that's probably one of the situations where you would precisely _not_ want synchronization. Now not only Google but your employer has access to your complete browsing history!

And exceptionally useful to put an unbreachable firewall between work and personal devices.

I think the majority of cases where it's helpful is between some traditional computing device, such as a laptop or desktop, and a mobile device such as a smart phone or small tablet. I think that's actually a fairly large amount of people.

That's also one of the situations it's most useful in, as having your saved passwords already present on your phone when you try to log into a site you generally don't from your phone is extremely helpful.

Well, most people. I use it to sync between laptop, tablet and smartphone.