Generally the only way to find a franchise QB is draft and develop though.
Out of all the good to great active QBs now, pretty sure almost all of them are draft and develop.
Brady, Ben, Rodgers, Newton, Wilson, Luck, Stafford, Flacco (I put him in cause SB win) Eli, Wentz, Ryan, Watson, (looks promising) I’m sure I’m missing more.
Only Free agent QBs that have had success are Brees became SD thought his shoulder was screwed, and you can argue Alex Smith a bit.
Way more than often draft and develop trumps getting a free agent QB