Flask is really good (and my preferred web framework, and full disclosure, I have forgotten how to write PHP), but it fails very badly at "no shared state," and depending on what GP meant by "a request" / "a response", it fails at that too. A Flask process handles an indefinite number of requests and responses; the built-in server handles them serially, and doing otherwise brings in either threads (and shared state) or multiple processes.

The Slack article posted elsewhere in these comments https://slack.engineering/taking-php-seriously-cf7a60065329 has some excellent arguments about why PHP's approach is different in interesting ways.

I have worked with Python/Flask, and I even built my own micro-framework on top of Ruby/Rack. It was nice, but I am far more productive with PHP, the workflow feels more natural than a cgi-like stack.

>>Have a look at Python & Flask! There is nothing easier than that!

What? PHP is significantly easier to roll out for your beginner/intermediate junior developer on a VPS. There isn't any comparison.

This comes from someone who leans on Python hard for ML work / scraping / signal processing (what it was born to do) and PHP for web development (what IT was born to do).

Laravel, silex, lumen, feathersjs, rails, zend, pylons, yii, cakephp, phpixie, are easier.