I know people who have had fires in their apartments, I have seen news reports on tv and the internet, there are entire subsections of literature giving excruciatingly grand detail of historical fires throughout time. You know, proof that a thing happened, and investigation of why and how it happened.
What I have not seen any proof of, at any time, from any source, is a mass infection of consumer grade smartphones which would have been prevented by ongoing timely security updates. Not one. Rien. Bubkas. What I am seeing a lot of is people convinced that a warning is as good as an experience which has been studied and learned from. What I'm seeing without fail in this thread are people so jammed up with "could" and "possibly" but no "here's what we learned from this exploit being detonated in the wild, and here's the reason it happened".
I like your fire analogy, I'm worried about fires, I've seen the results. The same can't be said about not getting ongoing manufacturers security updates for smart phones.