Is PHP obfuscation necessary at all?

Question

I saw this thread after wondering if a PHP obfuscator exists. It gave me the question:

Why is it necessary to obfuscate PHP code if PHP files aren't supposed to be downloadable/"decompilable" in the first place?

Answer 1

It's designed to obfuscate distributed PHP code. For example, say you're selling a forum system but offer a free trial. If someone can just go in and disable the payment check, then what's the point of selling it?

Answer 2

It's true that php-code cannot be showed/downloaded directly.

But, for example, you write a software for somebody else and don't want him to change anything on your software, obfuscation makes it harder for him to understand, what your code does.