I am not sure if part of the repairs that were done to my car were necessary.

Hello! I know it can be frustrating to have this kind of thing happen, and I'm sorry you had this experience. I will say that in the auto repair business, it's often very difficult to know what the "root" cause of a concern is, simply because the diagnostic process often requires a good technician to validate that certain parts are "known good parts". When the shop manual states to replace the ECU, that's step one. Once you have a known good ECU, you continue the diagnostic flowchart, and in this case, the fuel pump was condemned. As a necessary path of diagnostic steps, the technician is right to require the ECU replacement before continuing to condemn the fuel pump. It's very hard to swallow as the vehicle owner, but it is very likely the steps that needed to be taken. As an added note, a failed fuel system could be failed due to a processor issue within the ECU, and hypothetically one issue could incite the other issue to occur. I am sorry that it can seem this unclear, and am glad your vehicle is running again.