I have a two-part strategy to help with these paperwork jungles.
1) Like David in this thread has said, I am also most fortunate to have my spouse attend almost all appointments with me, so I begin forms and she completes them if I tire or cannot see well enough.
2) I am able to keep most of my medical care within the same medical system, and our system (Geisinger in Pennsylvania, USA), has a marvelous electronic patient records system. This allows us to print out a complete abbreviated health summary. This way, I just put my name on whatever form I am asked to complete and just write in “see attached health summary.”
My spouse and I often wonder if the physician we visit EVER looks at these forms that are often completed hastily before an appointment. So the attached printed summary is more complete and legible.