All discoveries use some element(s) of the scientific method.
The entire method in and of itself isn’t required to be 100% rigorously applied 100% of the time. However, the method is a starting point and does lead to discovery over time.
While it helps to apply the method to ensure clean and proper discoveries which can, hopefully, be reproduced and investigated, the fact that not all sciences or discoveries apply it rigorously is largely insignificant.