Because PHP is a amazing backed language for making CRUD apps. Always has been.

It has great web frameworks, a good gradual typing story and is the easiest language to deploy.

You can start with simple shared hosting, copy your files into the server and you are done. No docker, nothing.

Sure it has warts but so have all mainstream programming languages. I find it more pleasant than TypeScript which suffers from long compile times and a crazy complex type system.

The only downside is that PHP as a job means lots of legacy code. It a solid career but you will rarely if ever have interesting programming projects.