An IDE is mandatory to avoid sintax error, but tools like PHPStan or PHPCS are also mandatory to be sure you are coding in the same way your team colleagues ande your code is well indented.

Without this tools you (or your colleagues) could find tons of changes in github reviews when just a few lines were changed.

You can configure your commits as well to run these tools with others like CSSLint or ESLint before committing to be sure everything's fine (sintatically speaking).