This is a weird one. On vacation I wouldn’t hesitate to rent such a thing, but the idea of buying one seems silly to me.
Perhaps it’s because I usually ride alone and this thing pretty much requires two people to make it move. Perhaps because compared to a regular bike, or even two regular bikes, this is totally impractical.
It won’t fit in a bike lane. It won’t fit trough a doorway. It won’t carry much. So unless you have a garage and live somewhere that has really wide bike trails and have a constant cycling companion, this isn’t the bike for you.