This is certainly a true statement - but there are known technologies that provide better characteristics for scale than others (looking at big scale names such as Netflix as a start). Simply writing it off as “well they scale so fast, whatever!” is completely sidestepping the issue of using knowingly error prone tech at scale, and frankly is a bit irresponsible. (Note: this isn’t a statement on what CB uses or if they’ve tuned it appropriately or not)
Keep in mind that Coinbase always had to expect being banned by other companies if they adapt a no-crypto currency. I would've been very careful putting all infrastructure on some easily scalable cloud service. You'd probably want to be able to run with at least two cloud providers at the same time (preferably two providers from different jurisdictions). That means you'll have to build a lot of scale infrastructure yourself.
