Are you saying that PHP is only suitable for trivial non user-facing apps? We are in agreement! The reason you need to know all the edge cases though is becaus

Are you saying that PHP is only suitable for trivial non user-facing apps? We are in agreement! The reason you need to know all the edge cases though is because when you write a sigle line of PHP you need to know how to avoid the edge cases in that single line. Just because you are writing a short program doesn't mean the edge cases aren't there. Array keys getting converted to numbers doesn't suddenly start to become a problem when you hit 300k lines. If you don't know the edge cases then when you do need to write something more complex, or larger, or user facing, PHP is a terrible choice because there are so many edge cases that they are hard to completely internalise. Wouldn't it be better to write in something that isn't such a terrible footgun?