This is especially true if the majority of your customers are also on Microsoft/AWS/etc.
Literally 0 of your customers will notice that you are down if their own systems are also not working.
This is perfectly valid for many businesses, up to a (shockingly high) level.
LOL "if my competitors are all down too, then it's OK." I guess there's a bit of sense to that.
I didn’t say competitors; I said customers.
If none of your customers are up to call your service, it does not matter if your service is up or down.