...you lost me, I was expecting to read something like "as all the interesting stuff happens on the client side anyway" after the first part with using vanilla PHP, but you didn't, so you would either end up with a "thin-client + thin-backend" (which is close to... no site/app at all), or you end up with spaghetti. Care to share a github link of such a website or web-app to see for ourselves how easy it is to "pick up and implement changes within hours"? I bet it's more like diving headfirst into a pool of spaghetti once the project grows past a point...