[grubles]

>the whole system is only as durable as the increasingly-enormous data centers which hold all that information.

That is exactly what Ethereum's direction has been for years now. It is centralized on Amazon AWS via Infura's nodes (which they charge access to, mind you). It's not a world computer. It's EC2 with additional complexity (and fees).

[CryptoPunk]

Nothing consensus critical on Ethereum runs on Infura nodes. Plenty of people run full nodes on hosted services like Infura, but that applies equally to the original cryptocurrency and current number 2 coin.

The delegation of node operation to third party services is done more for convenience/up-time guarantees than any node operation cost considerations, and Ethereum would be fine if these third party services were all coopted or forced to shut down, because again, Ethereum's consensus protocol has zero dependencies on them.