This is maybe going to be an unpopular suggestion, but I think certain technologies are going to more commonly be associated with race-to-the-bottom markets, and I think PHP is one of those. It might make sense in investing in studying some more niche and higher-barrier-to-entry languages.
What languages do you suggest? Does Javascript have the same association with "race-to-the-bottom markets"? Having used Symfony and Laravel I don't understand why PHP has such a bad rep except that it's on the easier side so any language that makes things simple would suffer the same fate (attracting inexperienced developers (hello Javascript, Ruby, Python)). Both PHP and Javascript have many language specific issues…
If you haven’t done much other than PHP and JavaScript, I’d suggest going through the Seven Languages in Seven Weeks book, and also doing a bit of market analysis; see who’s hiring for which languages.