As a poweruser, I have installed new versions of Windows AND new versions of Android.
To the average user, neither is feasible.
To a technical user, both are possible.
I don't like this comparison. Many of us switch out AndroidOS's very frequently. It's actually not hard at all to install a custom recovery and load a different and custom version of android.
In fact, considering how defined the android ecosystem of alternative OS's is, and how undefined the Microsoft one is, one could easily suggest that Android is far less locked down.
After all, some Android replacements like Cyanogen/Lineage are far more developed and popular than Windows replacements.
1. Insert install disc/USB.
2. Boot to install disc.
3. Spam the next button.
Installing new Android OS versions manually often involves custom third party unlock tools from sketchy download sites.
I worked in a Computer Repair shop for years through college and believe me, the average user has ZERO interest in installing or re-installing an OS. They will pay >$100 to have someone "spam next a few times" as you put it.
I would call that a distinction without a difference. End result is the same: non-technical users do not do it.