Draft position has everything to do with it. If you use a 1st rounder on a guy, you are gonna want to see a return on your investment. It’s a proven fact that more patience & time is almost always given to players picked in earlier rounds.
The Bills wanted better production from the TE position probably bc they saw what Travis Kelce did to their defense ever year. Even if Kincaid is marginally better than Knox it still wasn’t enough to warrant picking him so early. You want a dominant TE in round 1 which Kincaid isn’t (yet.)
But yeah in the respective stages of their careers, Knox is the more well-rounded every down TE IMO. If given equal amount of snaps I don’t see there being much of a difference in production.