I believe that alot of FP+ go to waste. I know even as Disers we had several we didn't use. The system forces you to pick 3. We only wanted 2 at AK, but it made us pick a third. We didn't use the 3rd we were forced to pick so it went to waste. Our flight got cancelled and we arrived 6 hours later than we were supposed to- because of that, our only EPCOT FP+ we were going to be able to use was the one for Illuminations. It would not let us cancel the other 2- it was cancel all 3 or leave 3 in place. As such, 2 went to waste there. Also, if we weren't going to make one, and I tried to cancel- again it was an all 3 or nothing cancel- you could not cancel just 1. If
MDE was working- which it rarely was- you could move one to a different time or different attraction- but you could not cancel one. If there was no other time good for us available, we didn't want one for something else, or as we got one time "there are no other times or attractions available for FP+ in this park today"- then our FP+ went to waste.
We are WDW veterans (7 trips in the last 6 years- not counting trips before that), and I spent 3 hours tweaking our FP+ in hopes that I had a good guess what areas we would be in at what times so we wouldn't have to run back and forth across the park to make our FP+. We still found ourselves running back and forth until we decided we weren't stressing out about it anymore and were just going to miss them and use the paper FP system if they turned out not to be convenient. I can't even imagine what a newbie will be doing, if we had to run back and forth knowing the parks and how we usually tour as well as we do.