Is your priority to get a job or learn PHP?

French people, and by extension French Canadians, love Symfony. If you are looking for a PHP job in France, Quebec, or many parts of Europe Symfony is pretty much mandatory. However, when I read "I am looking for a job and so far I don't know any PHP-based CMS or frameworks" then you lump Drupal and WordPress with Symfony it makes me thing that you also don't know much about PHP? Are you a junior developer? IMHO Symfony is over-engineering at it's finest. If you are just starting out you will not get hired as a Symfony developer because most Symfony shops have pretty heavy technical tests you will have to pass before getting in.

"A Drupal and WordPress developer walk into a PHP meetup. That's the joke." If you learn WordPress or Drupal, you will learn a mutant PHP style that looks nothing like the rest of the contemporary PHP ecosystem. Again, are you a junior developer with not a lot of experience? If this is how you start learning PHP then it's pretty terrible but if you are just looking for a job it's not a bad option to start Both those ecosystems have talented developers in their ranks.

Finally you named 3 frameworks. Others in this thread have mentioned Laravel. I can name ~25 other decent PHP frameworks. There are probably more. You should look on LinkedIn for jobs in your area and focus on that. Good luck with the job hunt.