Holy shit, are we moving goalposts or what?
Now, it's the body type, not the age, got it.
If you think Mike Evans, who consistently ranks at the top of the NFL in average depth of target doesn't need speed to succeed, we're not even watching the same sport. Dude is the prototypical "go route" runner. And he has about as much in common with Adam Thielen as I do. Theilen hasn't had a season in the past 3 years where his average depth of target was higher than 9.5, and it was 7.5 last year. Mike Evans hasn't had a season below 12.1 and last season was 14.0. They have NOTHING in common as receivers, but apparently, they are some kind of unicorns with talent and a body type that Diggs doesn't possess?
But you want to know who has the exact same body type as Stefon Diggs. Marvin Harrison, he caught 95 balls for 1,366 yards and 13tds at age 33. Diggs is listed at 6'0, 191 pounds. Jerry Rice was 6'2, 200 pounds. Do I need to point out his numbers? Edelman was 5'10, 198 pounds, does he not count throwing up huge numbers after age 30? Torry Holt was 6'0, 200 pounds, had back to back 93 catch, 1,200 yard seasons at age 30 and 31. Isaac Bruce, 6'0, 188 pounds, caught 89 passes for 1,292 yards at age 32, and then had another 74 for 1,098 yards at age 34. Tim Brown was 6'0, 195 pounds and he was still catching 81 passes at age 36. Has Adams at 6'1 fallen off a cliff yet at age 31? Shit, Antonio Brown had almost 1,300 yards and 15tds at age 30 and would probably still be putting up numbers if he didn't turn into a lunatic.
I could go on and on, but the idea that there is some magical age in which guys fall off a cliff because of their body type is some new fangled shit. Guys get hurt, guys go crazy, but you can't distill anything down to some "well, he turned 30, and he's exactly 6 feet tall and weighs exactly 194 pounds and the last time that happened, the guy sucked...." theory.