You can update Linux without rebooting, except for the kernel (and even then there's options). Rebooting once a month is way more often than some of my Linux systems.
You can replace the open files on Windows (most oth time, see my other comment here), but the decision to reboot is not a technical one (and back in the days many invested in no reboot upgrades) but to have less headache on a corner cases.
no. restarting some daemons one by one when it's convenient is wildly different from taking down the entire system