Brand versus generic. Vyvanse or lisdexamfetamine?

"Generic medicines work the same as brand-name medicines
A generic medicine is required to be the same as a brand-name medicine in dosage, safety, effectiveness, strength, stability, and quality, as well as in the way it is taken. Generic medicines also have the same risks and benefits as their brand-name counterparts."

This is true for most people in my personal case it isn't.
I can't take generic drugs as they have no effect on me. For most people they do but everyone is different and are more or less sensitive to medications.
As I mentioned only brand name meds work for me which is very costly and wish generic drugs did work for me but they don't.