I think Debian is probably pretty conservative in their updates. I also recommend checking out the needrestart package. It will tell you when a reboot is needed because of a newer kernel that was installed, or when a systemd service needs a restart.

But as another commenter noted, outside of self hosting, in enterprise businesses environments where you manage an army of servers, things look different. But then, these guys are paid to be on-call in the weekend for events like these. :)