Platform companies can't scale by just getting more of the type of customers they already have. They scale by getting bigger and more demanding customers. Those customers will expect the things AWS and the other big cloud platforms already offer. And then R&D expenses explode. The bigger they get the higher R&D will be. In absolute numbers and relative to revenue.

Yes, it's true that if you become as big as AWS then economy of scale starts to work in your favor again. But that outcome is so unlikely it's not worth thinking about. The realistic best case outcome is that they become a mid-sized cloud provider, like Digital Ocean. And Digital Ocean, in business for 11 years and having raised 500m (pre IPO) is still losing money. Linode, after 20 years of struggle, ultimately gave up and sold for $900m last year. Even the best case outcome looks pretty bleak.