Last I used it, OpenBSD did a good job of compartmentalization. Like your cell phone or tablet, upgrades could be freely burn-the-earth-boil-the-seas, because user data and configuration was well-separated from the system files. Additionally updates were delivered in complete tarball form- you didn't upgrade eighty packages, you just unzipped one complete tarball.
It probably helped that the complexity was low- I remember the default install occupying some 300MB of disk and a few tens of MB of memory, in a time when Ubuntu already occupied some 10GB.
I question the comparison to cell phones and tablets. In those, upgrades have become painless because I do not value any data on them. That is, there is zero data that I would miss if I completely lost my tablet.
This works because I quit caring about the UI experience. I accept that when I upgrade, things will be dramatically different.
If I adopt a similar policy on my computer, I get similar results. However, as soon as I start actually caring about more and more data on the machine, things get tricky.
And this is where a lot of customizable user interfaces hit ridiculous trouble. Those customizations are rarely treated as important data. Worse, there is often a lack of ability to clean up excess preferences.
Which leads me back to my main point. There have been a lot of advances in consumer user applications that are easy to ignore in server applications. Which makes upgrading much more difficult in the consumer space.
I mostly made the comparison because my Android phone is partitioned similarly to how I remember the recommended scheme in 4.2-4.4 OpenBSD, and in both cases that partitioning scheme lends itself very strongly to painless upgrades.
But you are right about the lower "data risk" on phones, thanks to cloud services and such.
Is a fair point. But I think that we keep far less data on these devices than you ever did on a computer. Certainly not in the size of the data, but more in the types. Preference and general settings data has basically erased on these.
It probably helped that the complexity was low- I remember the default install occupying some 300MB of disk and a few tens of MB of memory, in a time when Ubuntu already occupied some 10GB.
That was more than half a decade ago though.