Coins are dead weight: they have to be collected, counted, banked and secured, and they cap what a site can charge. Moving to tap-and-app payment removes that handling entirely and typically lifts average spend per customer.
The bigger gain is control. Remote pricing lets you run off-peak promotions, adjust for utility costs and test price points without visiting site, while reporting shows which machines earn and which are idle.
For multi-site operators, that data is the difference between guessing at the next investment and knowing where it belongs.