Are we talking about Ubuntu, or Android? Because honestly in either case... what would you improve? Ubuntu has updates rolled into GNOME's package management frontend and it's seemed to work well, and Android has decent UX around updates (especially with A/B system partitions) although of course it suffers from vendors not actually releasing updates.
sudo apt install unattended-upgradesNot if you just want automatic security updates? The package is part of the server task, and defaults to installing security updates. It does not install other updates, and does not automatically reboot.
> Auto-updating security updates should be the default if you run servers in the wild.
It pretty much is (for Ubuntu server)?
Also, there are large number of "contenders" in the Linux based OS space which may have the UX you want, and if there isn't one this sort of thing tends to be pretty easy to tweak and suggest changes for (unlike in most of Google's OSes.)