You seem to be relying very heavily on the FED model being correct....
historically it's been very accurate, until we entered this age of near zero interest rate period that never happened before and people now have no idea how to value stocks vs. bonds... and financial planners are still telling people to allocate 60% stocks 40% bonds, complete blind to what is actually happening.
the model makes logical sense... the 10 year gives a guaranteed yield but zero growth, while stocks are volatile but has a growth rate.... so these 2 factors sort of cancel out each other, to call for a even par yield.