well actually not and the case for Crosby over Jagr at the same age is really rather strong BTW.
Even if that were true (it's debatable IMO), I don't know how relevant it would be, since their career arcs have been substantially different. I don't really see (nor would I expect to) people comparing past greats in terms of how good they were at age 18 or through age 28. What is discussed is how good they were at their peaks, in their primes, and over their hockey careers.
Let's look at some data.
First, where were these players through 11 seasons (each started their 11th season at age 28 and endured one partial season lockout during that span)? We'll project Crosby's current season, since he only has 23 games remaining and we have no other choice:
Crosby 708-337-594-931 (1.31)
Jagr 806-439-640-1079 (1.34)
Adjusted (using actual GP)
Crosby 708-365-626-991 (1.40)
Jagr 806-441-644-1085 (1.35)
That's pretty close, but I would favor Jagr's 94 more adjusted points in 98 more adjusted games.
What would Crosby have to do starting next season to match Jagr's career totals? We'll project each player's current season:
Jagr 1628-750-1113-1863
Difference: 920-413-519-932 (1.01)
Adjusted Jagr (actual GP) 1628-783-1151-1934
Difference: 920-409-515-943 (1.02)
So will Crosby be able to come close to playing 130% more games than he is projected to play thru age 28 at over an adjusted PPG? Considering he was ~1.21 adj. PPG last season and ~1.09 adj. PPG this season... and that he would have to play over 11 more completely injury-free seasons just to match the number of GP. That doesn't even factor in that Jagr missed an additional 1.5 seasons to lockout (nor address his 3 years in KHL)... and Jagr is still playing. Even assuming Jagr retired after this season, Bill James' Career Assessment formula (for baseball... and I think hockey players age roughly similarly to baseball players) would project Crosby to 1,650 career adjusted points and a 20% chance of matching Jagr's total adjusted at the end of this season.
Now let's look at their (extended?) primes and see how far Crosby is from Jagr's prime:
'95-'07 Jagr
Raw: 960-529-781-1310 (1.36)
Difference: 252-192-187-379 (1.50)
Adjusted: 960-559-819-1378 (1.44)
Difference: 252-194-193-387 (1.54)
Again that doesn't include a full lockout season during Jagr's prime. Will Crosby over the next ~3-4 complete seasons' worth of hockey score at ~10% above his career adjusted PPG? I think we can agree that's extremely unlikely.
Now let's look at their most productive scoring seasons in terms of adjusted points and also against median first line players (top 2N scorers, where N = # of teams):
Adjusted Points
Crosby 121, 116, 115, 106, 106, 99, 93
Jagr 144, 143, 130, 120, 117, 104, 98, 97
Vs. 2N
Crosby 1.54, 1.49, 1.48, 1.37, 1.33, 1.26, 1.25
Jagr 1.79, 1.65, 1.55, 1.51, 1.49, 1.47, 1.36, 1.23, 1.19, 1.15, 1.13, 1.12