We do not know whether Jones will be a franchise QB, but to say he won't be one is short sighted. Look at Joe Burrow. He is very similar to Jones down to people questioned his arm strength last year. And now now he is in the Super Bowl.
Yes, Jones has some limiting physical characteristics. He will never have Josh Allen's cannon arm. But he can develop his arm strength to make people not question his ability to throw the ball down the field like Burrow answered those questions this year with a much improved arm in his second year.
Jones cannot do anything about his height. But that is the only physical characteristic that cannot improve.
But Jones has a lot of the intagibles that few QBs have. He throws with anticipation and into tight windows. He reads the field better than most rookies do. He can go throw his progressions quickly and has a quick release. Those things you have or you don't. You can hone those skills, but if you don't have them you are likely going to have a short career. I think Zach Wilson may be in that category. A monster arm who wants to hit a homerun on every play.