The only workable reason for this change is to violate your privacy, every gun is serialized, they know immediately where it was bought and by whom from who for any commercial seller.
Private sellers are not using credit purchases, any who would use a PayPal or other credit market would be insane to do so.
This is more about doxing and exposing those who buy or a means to lock you out from a purchase than anything else. They already know what purchases are made in any commercial market selling guns.
I hadn’t thought much about it, but what you say makes a lot of sense.
This will do virtually nothing to uncover illicit sales.
It’s nothing but an easier way to track who is making legal purchases.
It’s kinda like why they gave everyone under 75k income covid money during the (way longer than 2 week) lockdowns, and it didn’t matter who lost their jobs or not. They did it that way because there was no easy way to sort out the populace, because the government is nothing but inefficient and antiquated bureau-bloat. A private IT database developer could write the query in minutes and set up the new tables and code in hours.
But I digress. The salient take-away is what you said. Nothing but a way to circumvent constituational rights by using the private sector as your proxy.