I do wonder that myself but I think from reading things on here and listening to podcasts the guys have used he extensive dataset to make sure that the result of the ramp test and subsequent calculations do properly give you an FTP which feeds into future workouts accurately.
When I say I wonder - it’s things like eclipse today that makes me wonder. First time doing 3x 20 mins efforts. Was really very challenging. However - and here’s my key point - it was doable. My HR was hardly above 150 and ave cadence 90. So when I say it was hard, most of the difficulty was mental. I know this is a common theme in a lot of my posts but that’s because it’s what I’m experiencing and learning. My wife will soon be sick hearing about the mental lessons I am learning on the trainer!
I’m also wondering how many folk are actually failing due to mental rather than physical barriers. My head told me I could not do this whole workout today but when I told it who was boss, my body did what it was told. 