I don't see how anyone looks at Gesicki and thinks he can be an elite TE. He can't really block, his route tree is limited to about 3 distinct routes, and he can't get yards after contact. Do you see any of those things changing over time? I'm assuming both the blocking and inability to break tackles is in large part due to him playing upright and not having the lower body strength. Maybe he'll put in the work and that'll improve but we haven't seen much evidence so far. The route thing I think is hopeless.
Hes big, hes fast, and hes got an incredible catch radius. He has a place in the NFL...just think you need a whole lot more from your starting TE.
Today's NFL is different than that of the past. If you honestly think anyone drafting Kyle Pitts is going to use him to run block and pass protect for 50% of his snaps, you are incorrect. Today there are two positions, and very few players can cover both. Those positions are referred to as "Move TE" and "In-Line TE" and just about every TE you see in the Pro Bowl and all of them on the All-Pro teams are Move TE's. Very few of them do much blocking at all these days.
Even in the past we had Kellen Winslow re-define the position and create the Move TE. He made the Hall of Fame because of his ability to receive the ball, not his ability to block. So while there are still a few Mark Bravaro types who are truly two-way players--and like you I cherish those guys because they're truly swiss-army knives--they are very few and far between. Take a guy like Travis Kelce, arguably one of those two-way players and the best TE in the game at the moment. He rarely run blocks and almost never pass protects. He can ... but his highest and best use is running routes. All of the stats discussed by fans are his receiving stats. All of the Pro Bowl considerations are looking at him as a pass catcher, not a two-way player.
So touting a rare pass catcher's average in-line blocking ability is not as relevant today as it used to be. We simply don't run as much, so the run blocking is less important. We now pay TE's good money because the Move TE is a subset of the Slot WR role, which has come into prominence today because everyone is running a variation of the West Coast Offense that uses short passes as replacement run plays to move the chains. A TE who can knife down the center of the field on a seam route absolutely wrecks some coverage schemes, opening up the entire passing game playbook for an OC. LB's can't cover them becasue they're too fast and the LB is quickly out of position. CB's can't cover them because they're flat out too big. Safeties are required to pick them up because they're the only ones who can physically have a chance at matching them ... and guys like Gesicki and Pitts are faster than many SS's, meaning the FS needs to abandon whatever he was doing and switch to deep coverage of that deadly seam route. Pitts is similar, but let's take a look at Gesicki for a second. When the QB throws the ball, no defender is as big (250 lbs.), strong (vice grip hands and powerful upper bodies), and long (6'6 with a 41.5" vertical) as Gesicki to dominate those contested catches. And after the catch, he may not be nifty, but good luck tackling him at the point of contact. He's usually going to drag you for an extra yard or three.
Discounting Gesicki because of his blocking is out of step with the current game. Yes, everyone would prefer that he be a better blocker ... but nobody wants him blocking very often, because his gifts are wasted if he's not out in the pattern. He's a modern Move TE. Anyone advocating for Kyle Pitts needs to understand that Kyle Pitts is also a Move TE, and trying to convert him to a blocker would be like trying to convert Walter Payton to a blocker ... it's just a waste.