[antihero]

> when you have to instantiate every object on each request,

The thing about this that it lends itself well to HTTP because HTTP is a request-based system.

Once you start breaking down the barriers between requests you get all kinds of horrendous issues with race conditions and memory sharing and pain. Sessions just about get by this because they are per-user and people don't oft do huge amounts of things concurrently.

PHP is also designed on a per-request basis.