I can think of a few possible reasons and they all probably play some role:
1. As already mentioned, not wanting to pay for additional photo rights if there is no staff photographer shot available. Card companies have to be frugal these days as the pie is much smaller than the Natrone Means rookie year days in 1993.
2. Photo editing/design software. It's faster to just recycle the same image than to start from scratch. Time is money.
3. NCAA exclusivity. This makes it tougher for companies to acquire images of rookies in early releases without resorting to airbrushing which, again, adds to the payroll. It is also frowned upon by collectors if not well done. Topps is likely only tinkering with this in Bowman to compete with the very early Leaf and Upper Deck sets in order to protect market share.
1. As already mentioned, not wanting to pay for additional photo rights if there is no staff photographer shot available. Card companies have to be frugal these days as the pie is much smaller than the Natrone Means rookie year days in 1993.
2. Photo editing/design software. It's faster to just recycle the same image than to start from scratch. Time is money.
3. NCAA exclusivity. This makes it tougher for companies to acquire images of rookies in early releases without resorting to airbrushing which, again, adds to the payroll. It is also frowned upon by collectors if not well done. Topps is likely only tinkering with this in Bowman to compete with the very early Leaf and Upper Deck sets in order to protect market share.