What is the fastest you have ridden a bicycle on flat land without wind? We can perform a basic watt equivalence.

Also, you seem hyper focused on power transfer being the sole reason for the stiffness of race bike frames today. What do you think maybe other reasons a frame is made stiff? I mentioned control...the rider's ability to control the bike when putting a lot of power into it. Why else may a manufacture place a priority on a stiff frame? Hint: your watt output relative top amateurs and pros that buy a given race bike is relevant.