> Right, but it's already doing that, and runs just fine, from what I understand. The developers don't have to sit there pounding the enter key on their keyboards over and over all day to keep the messages flowing.

It “works fine” precisely because there’s a lot of engineers pounding the enter key.

This is really just basic stuff, when you serve literally billions of users worldwide, you need a lot of people just to keep everything going smoothly as more and more people adopt it. Software doesn’t just magically scale to arbitrary usage and what made sense to build 5 years ago may no longer be the correct architecture today.