[romanhn]

I worked at PagerDuty, so definitely not selling availability theater. We did multi-cloud / multi-region for many years, and the story is not so simple. Development is all about trade-offs, and deciding what risk you are OK with. Multi-cloud provided a relatively small amount of value (given how incredibly unlikely whole-cloud outages are, even full-region outages are quite rare) at the expense of 2x implementation overhead, 2x exposure to random cloud-specific operational events, and the need to develop for the common denominator of functionality, which leaves out a LOT of interesting cloud offerings. In the end, it ended up just not being worth it, and moving to the single-cloud multi-region config provided enough reliability even for the company where reliability is the primary differentiator.

In my current job as a technical due diligence advisor, I frequently recommend multi-AZ setup but specifically not multi-region, because the former is easy and worthwhile while the latter carries a lot more operational overhead (you become much more sensitive to various latencies and network jitters) and you now need to think about things like synchronous vs async replication, etc. Much better to focus dev effort on the product, rather than eke out an additional .001% of availability (unless availability is a super critical component).