This isn't really Laravel specific, and it's also extremely subjective, but I'll throw out a few random thoughts (I'm normally good for that ;)).

According to the Tiobe Index, which folks generally find to be reasonable, PHP has been stable for the last few years. It had been booming for awhile before that before settling down; I think most PHP devs who were going to be, have already been dislocated.

As a developer, you'll undoubtedly be interested in continued learning, so never stop. I, personally, have chosen to double down on PHP and API Development. If PHP goes away, I'll still have a bunch of API development knowledge that'll translate directly to other languages.

In that regard, PHP isn't super unique. While it's not very much like Java, it is quite like a number of other common programming languages, such as Python and Ruby. Once you understand a concept in one programming language, it's easy to translate it to another language. If you're worried that the market will leave you behind, spend some free time building something in Python with Django, or with Ruby on Rails.

If you're good at what you do, and you have experience, it's unlikely the market is going to drop out from underneath you. But if you need that extra safety net, I think you'll find you have more than enough skill to pick up Python or Ruby on the side. :)