I guess I didn’t make my point well.
Without question, Fultz’s first year was a train wreck. But I’d argue that comparing a guy with a year under his belt (Fultz, or anyone else) to this year's draft prospects is meaningless — because a lot of the value of those prospects is based on a 90th percentile or better outcome which, by definition, most of them won’t achieve. Among last year’s first 10 picks, I’d say 7 or 8 are worth less now than when they were drafted (the exceptions being Tatum, Markkanen, and maybe DSJ), and I think that’s fairly typical. Fultz wouldn’t be a top-10 pick in this year’s draft, but neither would (for example) DeAaron Fox, and his 1st year was just meh, not terrible.
The right way of illustrating how much Fultz’s stock has fallen is to compare him to his peers who also have a year of experience in the league under their belts. Even a couple guys who had disappointing rookie years have leapfrogged Fultz, and that’s assuming he’d look fine in the private workouts he’d have to do if he were in this year’s draft.