Completely disagree. Our own Bob Lilly was one such mutant. There are always a few of these mutant types sprinkled through every era. Did you forget Too Tall? Joe Greene was 6-4/275.
And there are very few super mutants in today's NFL. It's about the same.
I'm certain many fans - especially the younger ones - only think this present era, or going back to the early 90s, has had great athletes, or as you say, "super mutants."
Sure, J.J. Watt is a special player. Reggie White ran a 4.65-4.7 at 295 lb and benched 500 lb. 15 years before Reggie, Randy White ran a 4.6 at 260 and benched 450 pounds 10 times. Mean Joe Greene was 275 and as great as Aaron Donald is (and he is a generational talent), how many NFL personnel experts would take Donald over Greene?
What about Gino Marchetti or Doug Atkins or Rosie Grier or Deacon Jones? And the 70s rolled out LBers who would just kill you: Butkus, Lanier, Lambert. Nitschke and Butkus in the 60s, and Sam Huff of the Giants and Bill George of the Bears before them.
The secondary was patrolled by guys like Dick Night Train Lane, Jack Tatum, Mel Blount. Running pass routes was much more dangerous in those days.
By and large, there's much more speed today. Training and nutrition will produce better athletes as time marches on. What if Bob Hayes trained today, had today's equipment, today's nutrition and ran on today's tracks? Would he run stride for stride with Bolt?
This all goes back - and my long post above addresses it directly - to the poster who said Staubach couldn't play in the 90s when Aikman played. Troy was tough - he was as big as Bradshaw and as mentally tough as Staubach - but Roger would have played in the 90s and would have put up bigger stats.
We tend to think of guys with much faster 40s. But the issue isn't a guy at 280 having a 40-yard run at a QB and hitting him with a lot more energy than a slower 250 lb guy. If you watch old games or highlights of some of the guys we've mentioned here, namely Lilly, Greene, the Manster, Olsen, Butkus, you'll see how they would fight off a block, get free and then just explode with perfect technique and power into a RB or QB.
If someone wants to doubt how Staubach would fare vs today's faster DL and LB, one should also ask how Tom Brady would fare in the 60s-70s when receivers were getting chucked all over the field and were not running as freely as they do today, and QBs had to hold the ball a little longer, when O-linemen could not extend their arms to pass block, and when QBs would routinely get drilled with a facemask planted in their chests or ribcages with no yellow laundry.
It will always be difficult to compare players across eras, but no. 12 for the Cowboys would be great in any of those eras. He'd run less today to avoid those concussions, and he might have had an even longer career for it.