Great question!
I think that 1 year from now we and many other teams will regret not doing just this. Both Waddle and Pitts (very different styles of of WR's) are guys who could go top 10 or late 1st. These guys have tremendous upside, and IMHO, Pitts also has a very high floor. Almost a can't-miss prospect.
Sorry to reply to my own post, but it felt a little late to modify it.
I missed the part about including Gesicki in the trade in the OP, and would add the caveat to my quoted post that if we trade up from 18 to get Pitts, that 's a smart move. But, Gesicki is already a better asset than Pitts, and our hope is that Pitts becomes what Gesicki has already become--a true mismatch that makes teams gameplan for him. Teams single-cover Parker. They gameplan against Gesicki. Him running seam routes makes it almost impossible to build a good scheme against, which is why we keep seeing him catching intermediate and long passes straight up the gut of the defense, and everyone keeps asking, 'how does a defense not know this is coming, and how have they not stopped this yet?' The answer is that he is a mismatch, a 6'6 guy with a 41" vertical, long arms and strong hands who excels at contested catches ... oh yeah, and he runs a freakin' 4.5 so LB's can't keep up with him and he dwarfs and outmuscles CB's. Only a S has a prayer of covering him ... and they're not going to do it successfully alone, so the scheme needs to keep one eye on him at all times.
Anyone drafting Pitts is hoping he becomes the exact same thing. Gesicki will command money, sure, but it's because he _already is_ that matchup monster that Pitts may or may not become, and it probably will not be as far progressed until he's had a few NFL years under his belt. At that time, who knows what the team needs will be, or how much his contract renegotiation will cost. Better to take the bird in the hand with a phenomenally high ceiling (Gesicki), than a guy who is almost as good in Pitts. Pitts is unlikely to be longer than Mike Gesicki (6'6 + long arms + 41" vetrical). Pitts is about the same speed, and about the same height, so we're probably talking about a similar ceiling for both players. But if you want better production and defense-threat in 2021, 2022, it's clear Gesicki is the guy you want.
My previous post was about the prospect Pitts being worthy of trading up. I realize now that I didn't make that clear. Sorry. My perspective was pairing Pitts with Gesicki, giving us two interchangable monsters who were both mismatch nightmares, and creating havoc for defenses. Essentially, both guys are big slot receivers ... but teams rarely have even 1 guy who can cover that. Making them plan to cover 2 of them ... that makes OC's salivate. At best, we have Parker as our #1, with Gesicki and Preston Williams playing those roles now. If we added Pitts, we would move Williams to be Parker's backup. We would also need someone with supreme speed to work in and keep the defenses focusing deep and opening up the underneath for Tua's bread and butter short throws, which are the staple of the NFL these days.