Perhaps you could, but you probably always could've built a clone of any SaaS app you wanted, it's just become faster.

I'm reminded of the infamous Dropbox Hacker News comment[1]. If you're looking at stuff like this thinking "what's the point? I could just make that myself" then you're not the target audience in the same sort of way Ikea isn't trying to sell stuff to carpenters.

This is true even when the barrier to entry in making these sorts of systems has gotten way lower.

1. https://news.ycombinator.com/item?id=9224