how old is your android version?

A few days old.

who should upgrade it?

Probably the organization that has used technical and business measures to make sure they're the only ones allowed to.

about Linux kernel and hardware drivers?

So Fuchsia will be another re-write that gets the credit for a design change that could have been made in the previous system? The only immovable object in the bad upgrade experience with current andriod is carriers/vendors. Google can push updates to their phones faster, I know, I watch them do it to my nexus quite often. Other linux-based systems have had smooth network-based component-wise upgrades for at least a decade.

I'm not trying to say that Fuchsia is a bad idea overall or that it won't make things better overall. But I'd like to see the case made on points that are fundamentally part of the new system. Everything so far all strikes me as taking the set of changes the old system has been in desperate need of for years, and tying those improvements to the "big change" to make the big change seem more worthwhile than it is on it's own. And a lot of this are assumptions that the new system will solve the outstanding issues rather than bringing them along.