I remember Meta having a few outages of their own. And outlook as well. So I'm not sure what to think now. But sure, on paper FAANG is redundant and hence better.
In my experience, issues scale exponentially with scale. So handling 10x the traffic might mean 100x the potentially issues. Redundancy helps with that so when something inevitably fails, the architecture is able to automatically recover and the end user doesn't see any degradation. So what works for lichess wouldn't work for Meta.