The static methods you are seeing are by and large facades -- convenience methods -- but Laravel is still absolutely "proper OOP."

https://laravel.com/docs/5.8/facades

"Contract" is not a term they invented; it's a term from "design by contract programming," and Laravel enforces the "contracts" through interfaces.

https://en.wikipedia.org/wiki/Design_by_contract

(And, no, they did not invent the term "facade," either.)