This is interesting. I asked Grok about this expecting to try to clown Mosher, but it turns out he's kind of right if I'm understanding what Grok is saying (it's wording it weirdly). There actually have been some studies on this.
"Younger prospects (typically those entering the league at 21-22 or younger) tend to have better long-term NFL careers and higher average production than older ones (23+), even after accounting for draft position in many cases.
A FiveThirtyEight study of first-round picks (2000–2013 era data, with patterns holding in later reviews) found average career value declining with age: players aged 20-21 averaged ~43.8 CarAV, 22-year-olds ~42.9, 23-year-olds ~39.5, and 24+ ~33.6. Bust rates (low-value outcomes) rose notably for the older groups.
A more recent breakdown of the past 10 NFL drafts showed younger players (23 and under, with 22 and under even stronger) outperforming older ones at every position group. The gap was largest at QB, WR, RB, and EDGE (e.g., 17% lower value for older EDGE prospects). Older prospects were less "valuable" overall in terms of career output.
Other models (e.g., regression on early-career AV or rookie production) have found that each additional year of age at entry correlates with lower expected output, even controlling for draft capital. Younger players are often seen as having more developmental upside and a higher ceiling, while older ones are viewed as more of a "known quantity" with potentially less room to grow.
This does not mean every young prospect succeeds or every older one fails—there are plenty of counterexamples (e.g., some late-blooming older QBs or polished veterans who contribute immediately). Age is just one data point among many (athletic testing, production, scheme fit, injury history, etc.). Teams have increasingly de-emphasized it in recent years due to longer careers, the transfer portal/NIL era producing more experienced older prospects, and successes like certain 24-year-old rookies making immediate impacts.
On "Pro-Readiness" Specifically (Immediate Readiness vs. Long-Term)
Older prospects (23-25) can sometimes appear more immediately pro-ready due to extra college seasoning, physical maturity, or refined technique—especially if they had later breakouts or extra years of reps. This is anecdotal and position-dependent (e.g., potentially helpful for QBs or interior linemen needing polish). Some front offices note maturity or stability benefits.
However, the aggregate data does not strongly support older prospects being reliably "more pro-ready" in a way that translates to better NFL outcomes. Studies on rookie-year production or early-career metrics often still lean toward (or show no clear edge for) younger players when talent level is comparable. Breakout age in college (earlier dominance against younger competition) is frequently a stronger positive signal than raw chronological age or years played.
For EDGE rushers (relevant to the Faulk/Mesidor comparison in the original post), older prospects showed notably lower career value in one 10-draft sample (~17% gap)."