Less than 62,400 Rookie cards for the year might be a good start. 10 years ago it was 7280 total rookie cards. 2018 - 3150 cards?
Get rid of the common /450 rookie card, get rid of the Gold Signature card.
Only have signature versions for the Round 1 and 2 draft selections. ( 38 players)
Parallel set for all the draft rookie - (recycled players don't get another rookie card)
Collecting a set of draft sig cards used to be a goal for a lot of collectors. Not now. Can probably count on 1 hand the number of complete draft signature sets by collectors.
Now people are only collecting team sets or even individual players. That has driven the demand for rookie cards down and the supply has increased to crazy levels.
Even something like Round 1 draft - Copper/Gold/Platinum cards, Round 2 draft - Copper/Gold, Round 3 draft Copper, Round 4+ draft parallel only would help.