There is a hitch to that: If a bar finds that patrons are waiting out the free-drink clock and not ordering booze, it can choose not to turn on the loyalty function. The buyback, after all, is a two-way street -- there can be no buyback without there first being a buy (or, historically, three buys). Digitizing the relationship only makes customer participation more essential.
This puts the power squarely in customers' hands: If everyone wants buybacks to be a thing, everyone needs to earn them. Which isn't a bad situation -- everybody drinks, then everybody gets a free drink; the bar stays in business, and the patrons all feel special and save a little cash for a late-night slice.
One other note: Not every potential Swing application is financial. The bar could just send a message for everyone to wish someone a regular happy birthday, congratulations on their getting engaged, condolences on their getting engaged, etc. If you're the one receiving that treatment, you're hopefully among the few Americans still getting regular buybacks anyway.