Also: lets not forget one very important and under-rated side-effect of PHP -- it lets you write server-side code that can leverage a 'public' address. You might think 'well, doesn't everything let me do that?' Not quite. On 'free' VPS servers they usually have 'ephemeral' IPs or IPs that change. So while you get free bandwidth and compute -- it's hard to actually do anything useful with it like run a service if you don't have a public address. With PHP it's assumed it will be accessed from the web so if you run it on free shared hosting you get that accessibility built in.

PHP is very good for writing services that cost literally nothing because you can run it on free hosts like 000webhost that give you everything you need to host complex services (upload, database, sub-domains, and more.) It's perfect for budget devs or maybe devs that want to make their infrastructure more resilient to ah... financial upsets...