why do ebay allow buyer to accept an offer seller sends them but allows them not to pay imediatley

[1972bear9]

i sent an offer to a buyer and they accepterd that offer,now ebay says its sold but the buyer although theyve accepted the offer to buy did not pay immediately as normal practice. why do ebay allow this almost semi scam...when i recieved mesaage that id sold the item i got it ready for posting and just checked again on my laptop from my phone as more detail to see that ithad NOT been paid for and therefore not actually sold. why do ebay allow this thanks

[tobiasd4]

For BIN with instant payment, buyer hasn't bought until they pay.

With an offer, because seller has to accept or counter offer, buyer can't pay immediately as they have to wait for seller confirmation.