Paper tickets were the only affordable alternative when we visited Paris for a week during the summer. There was a "pay-go" card that cost a bunch upfront and y

Paper tickets were the only affordable alternative when we visited Paris for a week during the summer. There was a "pay-go" card that cost a bunch upfront and you could charge it with 10 or so trips at a time (and you couldn't share it either, so each family member needed a separate one). I've used Bolt (a cheaper Uber alternative) a bunch, though taxis in general don't seem very family friendly (several cars refused to pick us up - a family of 4 - because they apparently only take 2-3 passengers in the back seats).