I’ve actually never used Venmo, but when traveling with friends I have often used Splitwise. It’s good for travel because often someone has paid the hotel, usually a sizeable expense, and the rest of us want to make sure that person doesn’t end up being out anything, but keeping mental track of whether the rest of us have paid for roughly enough things to balance it out gets complicated. It was also extremely convenient in Thailand when I ran out of local cash but my friend still had lots — she paid for me for the last two days, we noted it, and I paid her in American dollars when we got back. She was able to use up her Thai baht and I didn’t have to withdraw any extra.
But if my friends wanted to use it every time we went out for a meal or a drink, I would lost my mind.