With docker containers and the numerous PaaS/FaaS runtimes, does that really matter? You can run anything just about anywhere these days, cheaply or even for free.
For average business owners who buy a WordPress template and some 5€ hosting in order to set up a business card web site on their own, on the other hand, it matters a lot. So if your project targets that group of people then PHP is pretty much the only option; anything more complicated than an FTP upload/MySQL import is pretty much to advanced for them and they generally aren't interested in learning new skills just to get a web site online.
The last thing a non-techie business owner needs is to worry about setting up a random server with bad PHP code.