My experience is that very few companies actually need those 9s. A company might say they need them, but if you dig in it turns out the impact on the business of dropping a 9 (or two) is far less than the cost of developing and maintaining an elaborate multi-cloud backup plan that will both actually work when needed and be fast enough to maintain the desired availability.

Again, of course there are exceptions, but advising people in general that they should think about what happens if AWS goes offline for good seems like poor engineering to me. It’s like designing every bridge in your country to handle a tomahawk missile strike.