214 GB per day is only unsustainable when you take the 'everyone must be a fully validating and archiving node' approach. This was not what Satoshi described.

"Only people trying to create new coins would need to run network nodes. At first, most users would run network nodes, but as the network grows beyond a certain point, it would be left more and more to specialists with server farms of specialized hardware"
http://satoshi.nakamotoinstitute.org/emails/cryptography/2/

"Another way [micropayments] can become more practical is if I implement client-only mode and the number of network nodes consolidates into a smaller number of professional server farms. Whatever size micropayments you need will eventually be practical."
http://satoshi.nakamotoinstitute.org/posts/bitcointalk/318

"many nodes will be server farms with one or two network nodes that feed the rest of the farm over a LAN."
http://satoshi.nakamotoinstitute.org/posts/bitcointalk/188/

"Visa processed [...] an average of 100 million transactions per day. That many transactions would take 100GB of bandwidth [...] If the network were to get that big, it would take several years, and by then, [...] would probably not seem like a big deal"
http://satoshi.nakamotoinstitute.org/emails/cryptography/2/

Quotes collated via this Reddit post

214GB per day is perfectly affordable for a datacentre. That's 78 TeraBytes in a year and a single hard drive can store more than that today. The other issues of bandwidth and replay time are also perfectly solvable even with huge blocks.

The cost of this is that yes, as Satoshi expected, not everyone will be able to run full nodes on consumer grade hardware. There is an argument that this makes the network more vulnerable to state attack, but on the contrary, keeping it small to the point of irrelevance makes it more vulnerable in truth. History shows us that clandestine organizations are well capable of amassing resources to run large scale operations.