LOL If anything, a more barebones internet scales better. The less data you're sending, the more connections you can handle simultaneously, and the less code you'll need. When communication is more decentralized, there's not much of a need for most sites to need to think that much about scaling. We don't need the next Facebook or the next Reddit. I'd love to go back to more independent forums. Maybe with something better than vBulletin, at least.
nimforum*, which powers the official Nim forums, doesn't scale for shit, yet totally works for the scale of that community. not everything needs to massively scale, and, in fact, I think the mistaken belief that everything has to scale has led to many people being dissuaded from building smaller communities like back in The Old Days.
You are not Amazon. In the unlikely event you become Amazon, you will be able to rearchitect. Trust me, Amazon did.