I don't know how many times I need to say this, but I will die on this hill. Centralized services don't decrease redundancy. They're usually far more redundant than whatever homegrown solution you can come up with. The difference between centralized and homegrown is mostly psychological. We notice the outages of centralized systems more often, as they affect everything at the same time instead of different systems at…
I have a cheap VPS that has run reliably for a decade except for a planned hour of downtime. Which was in the middle of the night when no-one cared. Amazon is more reliable in theory. My cheap VPS is more reliable in practice.