This point makes a lot of sense and if you made it a personal rule (I rarely draft 4th+ round WRs, but love 2nd-3rd round WRs), I would not blame you. In this case, I am willing to consider that:
1. The GM said he would have taken Carter at 66 had they not traded the pick. So, the Jets had him valued as a 2nd rounder.
2. The depth chart above/around him is inarguably terrible. Tevin Coleman is garbage and he is the literal top-of-the-heap.
3. He was pick 107, the 2nd pick of round four. If the Jets had traded up 4 spots into round three, would Carter now be "acceptable" to pick, since he was a 3rd rounder and 3rd round RBs have higher success rates? While true, seems a tad silly to be so cut-and-dried on this. Just like any rule, when you make an exception, when do you stop?
4. He averaged 8 yards per carry in 2020 and 6.6 in his career.
5. Played opposite another NFL-caliber RB (Javonte Williams) yet still commanded exactly 50% of the touches.
But if you consider all factors, and if you had to bet on who had the most PPR points at RB on the Jets in 2021, what are Carter's odds? Is he the fav? If not, what about in 2022? Beyond the "2022 three-down-back-top-50 pick concept", who beats out Carter going forward? And why would the GM invest a top 50 pick in RB in 2022 when he though he got one in 2021? It is up to Carter to fail here. Doubtful that he does and his price is cheap considering all of the above, IMO.