Hey, welcome to our forum!
Ok, wfp is great for maintenance cleanings and high up windows ( if you dont feel comfortable on a ladder or perhaps its unsafe for a ladder).
I personally think ground level windows and really dirty windows are better with trad tools. Especially like ccu window cleaning jobs.
This question could probably be answered a different way by every window cleaner. I personally think that wfp is just another tool in your arsenal.
Learning when to not us wfp I think is one of the most important things to know when owning one.