Building something, updating it, running it, testing etc. still requires resources and attention. One example for this would be taxis. You pay for the comfort of not having to drive the car, do maintenance, take into account road works, cleaning, etc. and not because you couldn't drive a car yourself. That time you can use instead to focus on your actual business.
The owner at my current gig has multiple times said "software is over" as it being a sort of gravy train of rent seeking. Products are gonna have to offer real / significant value to attract new customers. Maybe even to keep them, too...
This sounds good in theory but - and I speak from experience with a FF system causing a system-wide outage - clients don't care why YOU had an outage, or that it's not immediately your fault, and they really shouldn't have to. The reality is more like you're paying for a dependecy that you can't mitigate.
Given that every FF system comes with a bunch of different mechanisms that prevent your system from being catastrophically impacted in case the provider goes down, its still the fault of the integrating party if you experience an outage due to a FF provider.