Age seems to impact rather Early. Which seems weird, since these guys already 'developed' and you know what you're getting.
https://mfn7.myfootballnow.com/player/4181
This Super Stud (S Kenneth Fletcher) is 27 Years Old, still in his Prime... worth 1950. Now, that's not a bad value, but DT Gabriel Sexton
https://mfn7.myfootballnow.com/player/5219
is a hefty 2340 in Trade Value, despite having a good ways to go to reach his Max Potentials (though his Growth is good, so he SHOULD hit Max). While Francis Humphreys
https://mfn7.myfootballnow.com/player/4719
is only worth 1040.
None of these guys are 30 or nearing Retirement, or at an age where they should be at less value.
However, they all play different Positions, so that could be Positional Value weighted in.
Just showing 3 guys at different spots to get an over view of things.