We are still waiting for PHP 8 Driver. It's very sad to hear that you can't work on it. We would like to be able to work with Cassandra in PHP world too. Cassandra is further developed in all other programming languages except for php. I'm jealous. We don't want to look for an alternative.
Update: People from Nano Interactive working for PHP 8 version: https://github.com/nano-interactive/php-driver