Yeah, this is exactly what I thought when I read this post. It seemed like the author either hasn't worked in big tech, or hasn't worked in the industry very long. It's extremely likely that the engineer who designed this was standing on his desk shouting "it's going to cost THIS MUCH MONEY. I want to make sure that EVERYONE IS OK WITH THIS." and was met with shrugs.

Here's how a big tech reporting chain sees this situation when everything is smooth sailing: "We're growing 3x year-over-year? After 2 years, the cost will be an order of magnitude higher no matter what solution we pick. The constant factor doesn't matter that much. But we have such an incredible roadmap that we will book more than an order of magnitude of revenue, backed by this new ledger project. The cost will always be a nonissue because of growth."

And then 2 years go by, and this incredible product growth adds a bunch of ledger entries that weren't there 2 years ago, someone nudges your reporting chain with the question, "this is pretty expensive.. what gives?" and then someone with a good combination of social and technical skills points out that a migration to your existing storage solution would be a cost effective way to continue growing.

At every step of the way, everyone is generally happy with what's going on.