Joris Vaesen

Adds important value to the language. As I'm almost always programming against interfaces, this would help reducing boiler plate code a lot.

Waiting for this for so long! Can finally ditch al the MyClass::create() static constructors.

It adds complexity, it can be confusing, but i think it's an important step forward for php to implement such feature.

For the readonly vs. asymmetric visibility discussion: you can mix them up since they aim a different goals (write-once vs writing from).

With First-class callable syntax available since 8.1, it would now be possible to write it as below, which is much better then string names of functions:

$result = "Hello World"
    |> htmlentities(...)
    |> str_split(...)
    |> fn($x) => array_map(strtoupper(...), $x)
    |> fn($x) => array_filter($x, fn($v) => $v != 'O');