eBay has been testing ways to confirm payments from auction bidders / winners for a while, for those in the test, it asks for a payment method up front and gives a grace period of around 3 days post-win before the debit or charge is made, but I'm not sure if it will ever be implemented in full, and honestly I just take significant patterns or changes in buyer behaviour as an indication to adapt.

Years ago, everything I listed was an auction, then I did a lot of Buy it Now with Best Offer, these days it's exclusively Buy It Now, and I haven't had a non-paying buyer in years (as far as I know, anyway, I check every few months out of curiosity, but I have it set up to automatically cancel orders that aren't paid for within a set time, so there may have been some that I never even saw - much better to never even have to think  about - much less chase after - bidders who don't want to be buyers, IMO).