Allen took just over 200 hits last year and it looks like he’s not letting up. In the Sims interview he mentioned how he felt the physical toll of his style of play, after games and after the season. Cam was never as good a player as Allen (even at his best) but he was every bit the physical specimen Allen is and Cam broke down at 30. So longevity is the issue here.
Allen should and deserves to enjoy a long career because he does all of the QB things at a high level both in terms of execution and football smarts. Thing is his running the ball, both designed runs and even more when plays break down would be a huge asset to give up - important third down conversions and some game breakers, and with regularity. He’s young and he’s strong so maybe it’s ok if he does this for a handful of years and then tapers off.
The only thing you worry about is injury and here like others I don’t think he’s cautious enuf. Does he really have to truck that linebacker?