How often do you shutdown / reboot your personal computer(s) and why?
You only have to step into a debugger and examine memory to see data does not get cleaned up, which is why things like windows and other OS's are being re-written in memory safe languages, that clean up behind themselves.
https://en.wikipedia.org/wiki/Terminate-and-stay-resident_pr...
How often: Once per week for my workstation and all my servers and firewalls.
Why: Uptake the latest LTS kernel that is built weekly, sometimes once every two weeks depending on if the OS providers deem them important enough. Sometimes I will wait a patch cycle depending on what is in the changes [1].
And I never shutdown my work laptop after work, I just use sleep / hibernate. Maybe I install Windows updates every few months.