I guess it just depends how you're measuring things. For example, I would say that Clover POS systems are everywhere these days. You could counter by saying, "Well, Walmart doesn't use Clover and I wouldn't be surprised if they ring up more transactions daily than all those small businesses with Clover devices." Both can be true.
I bet the average person visits at least one PHP-driven site per day, even if they tend to stay within the confines of social media and YouTube. You might check the menu of a restaurant, visit a local government page, click a link to a news story or blog, visit an ecommerce site. Facebook might not use a lot of PHP anymore, but when you click on an ad on Facebook, it'll probably take you to a webpage driven by PHP.