That's not an "all-in" cost though, as long as businesses still have expenses in dollars accepting fiat for goods and services will remain be cheaper than Lightning PLUS exchange spreads.

As a spender I also get that percentage back and then some, and bear 0 risk. There's a massive cult around airline shitcoins too that will never give that up. I've personally paid the 3% up-charge at superette because who wants to go to an ATM all the time?

I do think there is room for it in remnant cash business, where arbitrary banking issues exist, weed stores were a good example Mallers hit on in the earliest days... gun stores faced censorship issues too... these are again areas of hostility not unlike the internet. Empirically there's been no market validation outside areas of hostility.