Upvote:1
See for example https://thepointsguy.com/2015/08/fully-refundable-airfare/ (US centric though).
Most airlines still offer full-fare Y tickets but you may have to specifically ask for them since no one in their right mind would buy them. They tend to be extremely expensive. I just checked a BOS-HKG itinerary on United and it was $800 vs $5300 (both Economy!). The same day walk up fare for this trip would be around $1200 and you'd better off just holding off the purchase until you are sure you need to fly