This is bassakwards. As a buyer I have completed my obligation when I submit payment and should receive positive feedback as soon as possible from the seller. On the other hand I reserve the right to receive and inspect my purchase before leaving feedback for the seller. I absolutely NEVER leave feedback for a seller that hasn't left feedback after payment unless the product or delivery does not meet the advertised expectations in which case I will neg you.
When I receive an item that is as advertised and the seller has left my positive feedback for immediate payment I ALWAYS leave positive feedback for the seller as soon as possible. Bonus comments for good communication and questions answered if any.
Sorry, but I think you have it backwards.
Today, with most eBay sellers being large companies making sometimes hundreds of sales per day, they leave
feedback automatically as soon as the payment is made.
eBay grew out of selling used stuff by auction, and the established procedure was (and is) for the buyer to
get their item, inspect it, approve it, then leave feedback. The seller then leaves feedback. Sellers
used to be able to leave negative feedback on a buyer, but no more. So the buyer can be honest,
without fear of retaliation. The buyer should leave 5 stars for all criteria unless there is a problem
that the seller does not resolve, after making honest attempts.
I have been buying and selling on eBay for more than 18y now, and the feedback system is still
important, esp for buyers and sellers of used stuff by auction. Sadly, most buyers today do not
seem to leave feedback at all.