Well... you know, this is tough...
Fundamentally, I don't have a problem running a Full Read Option or 3 Option offense... where any or every play the QB has the option to pass, handoff to RB or run the ball himself. Michael Vick seemed to do OK as an Option QB. In his 6 seasons with Atlanta, he only missing most of one season due to injury. That's probably not far from average for NFL QBs. Not that Vick is the rule, but that talent is rare too.
That being said... just because a QB can run well, and can run the Read Option well, doesn't mean it's the right scheme for that QB, that OC/HC, or that team. Is it right for the 2021 Bears? I don't think I'm privy to enough info to say.
I think Fields has the body type, thicker and strong, 6'3" 220, to take normal hits as a QB that runs... but more importantly, from what I've seen and understand, Fields is experienced and trained to know how to rush with the ball and deal with tackling defenders is a reasonably safe manner, primarily to avoid contact altogether.
OC Lazor used Trubisky and the 2020 Bears OL fairly effectively in the Read Option for a series of games at the end of the year, amassing 30 pts per game. And that was with Trubisky who is not particularly good at the Read part of the Read Option. They played crappy defenses, but they executed well.
So I'm not recommending Fields be used in Read Option, but I don't have a stern aversion to use him that way. But I do mostly agree with you: I'd rather keep him healthy and in the pocket for a long career... and anytime he can safely scramble for good yardage that's great too.