I think all of that is mostly irrelevant. You don't need to pay a huge cost to avoid the small benefit, you don't need every service to be resilient to this, or any of that. You just need multiple different providers so that not everyone gets screwed at once.
But that would require companies to actually spend time and money testing and working with either a cross-provider multi-master-type system (with all the associated consistency headaches) or regularly test a functioning disaster-recovery/fallback system.
The time spent on that (let alone cost, for companies with large amounts of data) far outweighs the cost when a single region has an issue of today's scope. And you said it yourself, it's a 'small benefit'. Small benefits sound like exactly the things not worth spending time or money on.
For as much as many companies have had issues today, the daily reality is that these same companies haven't been having issues all the rest of the time (or this wouldn't have felt so shocking) and are likely to be okay with an outage of this scope (plus, everyone's too busy making noise about the issues to be working normally).
There are multiple different providers, with nothing artificially limiting their use. Also idk what's so bad about Fortnite and Snapchat going down at once instead of it being staggered.
The three you mentioned have over 60% market share which is why this article exists at all. Knowing what I know about cloud ifnra, anyone who is actually anyone is hosting on the big three. So it's not just a market share, it's market share + impact / importance.
You could also argue that YT is on GCP (to some level) and that would probably bump that number up much higher.
The vast majority of people hosting things on the internet are on these providers. But you get downvoted for pointing that out now.
