AC is not required as the standard manufacturers warranty should cover any faults for a year or two depending on where you reside.
Many (most?) countries provide only a year. Logic board replacements; failed keyboard and ports; etc. can be quite expensive, yet easily covered by AC for years 2 and 3. Well worth it for many people, especially given varying quality control over the years.
My place of business provides it for my laptops and I've used it several times, saving thousands of dollars, on component failures and manufacturing defects.
I take care of my belongings so have never suffered any damage on any laptops, iPads, iPhones, TVs, etc… there’s no way I am paying hundreds of dollars each year and then an additional excess for an iPhone when I can stick it in a case, use a screen protector, and not treat it like trash.
I assume you didn't mean anything by your lede, but “I take care of my belongings” has always troubled me in these discussions of Apple Care. It comes off as smug and patronizing — and suggests that others, especially those who get Apple Care, are careless people who don't take care of their valuables!
Plus, as the stock prospectuses say, “Past performance is no guarantee of future results!” Come tomorrow you may wish you had it!
As Mirollin noted, accidents happen. Dogs, cats, youngsters, inadvertent spills, roommates, walks across campus or on city streets, others bumping into you, etc.
I'm very careful of my belongings, but I know that life happens so I typically get Apple Care, especially on portable expensive devices. Now, it pays to determine out of pocket repair costs, and the fairly large deductibles, to see whether the cost-benefit ratio is to your liking.
But
categorically dismissing AC as “not required” — because the products come with a 1-year warranty (sometimes 2) or because one insists one is “careful” — is ignoring the out years, other people's situations, and even being a tad myopic or overgeneralizing!