PHP is Much Better than you Think
Let me start by saying that PHP is a great language to learn and it has great value to many developers. However, this is not a simple yes or no answer because it is dependent on several factors.
There are a more languages out there. To narrow it down to one or even a few and say that ‘these are the best’ would be misguided. Mobile, database, Front end, Back end, and on and on. Forget the money or whatever is motivating this question and find what you like doing Programming will probably be a lucrative skill for a long time
Salaries change based on need. As technologies change, as business needs change, so will the top paid skills, as far as programming. For example, Swift is Very popular right now due to the rise in the mobile programming market. However, it wasn’t that long ago that Objective-C was the ‘go-to’ for iOS and mobileou must change with the times if you want to stay on top. That means committing to lifelong learning. It doesn’t mean you will learn every language, but having a good working knowledge of many will serve you well.
Others have said this but I will reiterate – knowing the language doesn’t make you valuable, solving problems does. You can take a ‘boot camp’ course in many languages and learn the core of it in a very short time. As with many jobs, though, it becomes very different when you get into the real world. Hone your skills and, over time, you will be more than a programmer but a solver of problems. That is what is valuable to an employer.