Phalcon is currently disappearing as a php-extension for php 8.0. The project is not pgrading the zephir compiler for php 8.0. Instead the entire framework for phalcon 5.0 is being adapted to php code for version 8.0.
Until all dependencies are reimplemented, some phalcon php code may find that acceptable peformance still depends on an implementation supplied by a php extension written in C.
This is good. Extension phiz, is to be a non-zephir implementation of these core functions.