I once wrote some PHP. It's the worst language. I can't believe anybody would write a respectable compiler, for a respectable language, in this junk.
Also, all these "real websites" also have very real problems that come from using PHP.
Also, this is completely besides the point.
The statement "It is possible to write good, or bad code, in any language" (1) might be true, but it misses the point. Consider "With or without cancer you are going to die" which universally true for all humans (as far as we know). But it also misses the point if applied to the question of whether you want to have cancer or not.
Particularly, your statement (1) is irrelevant to the question if it is a good idea to use PHP to make any kind of software that is functional, maintainable, reliable, secure, scalable etc. And anyone who has actually programmed in PHP knows, that just for example, it is VERY difficult to make a secure PHP program. Just because there are a thousand non-obvious ways to shoot yourself in the foot which are directly caused by weird quirks of the language. It might be possible to get this right, but if it is, it is a lot more difficult than in a language with e.g. sane rules for type conversions.
If you think all programming languages are equal, then you still have a lot to learn.