> Can't you just have the coin-operated parking meters back? Where I live, in EU, parking meters even take cards.

That costs money. Coin operated machines routinely are targeted by vandals, with each case making easily 100x the damage for loot. And card-acceptance also has its issues, the terminals need a data uplink, someone needs to take care of the machines. That's why so many (especially private parking lots) shift over to purely app based schemes. Orders of magnitude less tech you need to worry about.