Any language is worth learning, but I'm not so hot on PHP anymore. I use it for websites for customers so that they can find cheap hosting, but I mainly use Node for newer projects and even started actually using Python for some projects. It's an easy language to learn and use, but that's its' weakness. There are still many many jobs for it and it powers like more than 90% of the web (don't quote me on that)...
Why not learn Perl? It's more fun.<p>PHP is used everywhere so it can be good for getting a job. Better focus on "modern" PHP then. Lately I am seeing a shift towards Nodejs so if you don't mind using JavaScript that is perhaps more popular with "cool" employers.
If you ask a php dev they will probably say yes. If you ask a python dev they will probably say no.<p>So its up to you :-) Ask yourself will it bring you joy? if so do it if not do something that will.