Reb,
“Gaon, “How come Tosfos (quoted earlier) couldn’t’ come up with such a tekana?” That is an unanswerable question. But the same question can be asked about any innovation in Torah (e.g. chiddush of an achron that answers a question from a Rishon), one can (but doesn’t) ask the exact same question, why didn’t earlier doros come up with that?!”
Sorry, but you are technically wrong; you will always find proof and refutes like that in Achronim, “so how come Tosfos didn’t answer like so and so” !? Usually when an Achron will say another tirutz it will be with the hakdamah of “lulai divrei tosfos” and will (almost) never be leHalacha.
That’s a kalal, especially when dealing with some simple solution like Jo and you have..
R Gershom came up with the most exploding tekanos in his times and no one ever tried that…?
“If Hillel would have suggested a pruzbul in the CR, he would have been mocked and called a troll. (Ok, I am trolling now).”
Yes, you are aware that only someone like Hillel has the power to impose such tekanos,
It goes back to the old klal (despite Josephs dreams) : “we do not have the power to be Gozer any new gezeros.”