Partly agree. I once installed Firefox with uBlock Origin for someone who was Chrome user on an old PC and complained it was slow when browsing, and they told me that they didn't even know that there were different browsers available.
I'm the IT guy to most of the elderly people in my life, and steadily switching them over to Linux Mint over the years. Fact of the matter is, most of them use their OS as a gateway to their web browser, and don't care to do anything else with it. For many non-technical users, switching OSes is literally a non-thing. The only difference vs Windows is that they call me for assistance way less frequently.
I have family that would gladly use FacebookOS if such a thing existed and automatically loaded that and only that website as soon as you turn on the computer or phone.