And it's cheap enough that you can have replicated setup across two different providers and still be cheaper than one expensive cloud provider.
While AWS is probably towards the safer end if you want to put all your eggs in one basket, people are still putting all their eggs in one basket if they have everything at AWS as well...
But I think "redundancy" is more like a spectrum, rather than a binary thing. You can be more or less redundant, even within the same VPS if you'd like, but that of course be less redundant than hosting things across multiple data centers.