$ apt install unattended-upgrades

    # /etc/apt/apt.conf.d/99unattended-upgrades-custom
    Unattended-Upgrade::Sender "Root at servername.domain.tld <servername.domain.tld@servicesdomain.tld>";
    Unattended-Upgrade::Mail "services@servicesdomain.tld";
    Unattended-Upgrade::MailReport "on-change";
    Unattended-Upgrade::Automatic-Reboot "true";
    Unattended-Upgrade::Automatic-Reboot-Time "05:00";
    
    $ sudo systemctl edit apt-daily.timer
    # Opens a new file /etc/systemd/system/apt-daily.timer.d/override.conf, paste this content:
    
    [Timer]
    # Reset the system calendar config first
    OnCalendar=
    # Set a new calendar timer with a 60 minute threshold
    OnCalendar=*-*-* 03:00
    RandomizedDelaySec=30m
    
    $ sudo systemctl edit apt-daily-upgrade.timer
    # Opens a new file /etc/systemd/system/apt-daily-upgrade.timer.d/override.conf, paste this content:
    
    [Timer]
    # Reset the system calendar config first
    OnCalendar=
    # Set a new calendar timer with a 60 minute threshold
    OnCalendar=*-*-* 04:00
    RandomizedDelaySec=30m

There's few user space packages I imagine even benefiting from a reboot. Restarting a long running daemon is pretty painless. Also on a warm running system you've got an active page cache so all the unchanged files that service wants to open are likely cached in RAM rather than read from disk.

While I appreciate the flexibility low effort VMs provide I think they've negatively affected the views of Linux users. Long uptime is fine and restarting a whole machine is rarely necessary. At the same time modern systems with crazy fast SSDs make a reboot take little longer than just restarting a service.