> When you load a PHP page, it parses the code and initializes the app for each request. It then tears everything down after the request. There are less wasteful ways (most recent are app servers, just like in Python or other langs), but I'm not sure if those are widely used in local development.

There are things like opcode caches that make PHP more efficient transparently, while still feeling to the developer like a reload each time.

There are reliability and development advantages to starting each request from scratch. NO leaks, no state you need worry about.

PHP is very much like serverless.