The alternative is to pay on the way out. Requires a single terminal at the exit (or just anywhere, s.g. at the bar). It works perfectly fine. Cafes and restaurants across Europe do this more or less as the standard, the more fancy ones bring the terminal to the table.

I don't know about "Europe", but in France it's pretty common to get the terminal at the table, even at "non-fancy" random eateries.

Sure, you could pay on the way out, but that's often painful. Many others are having the same idea, so now you have to wait around, lining up in a place that wasn't designed for people to wait around, bothering waiters who need to run around serving clients. It's usually less of a hassle to just wait around at the table for the waiter to bring the terminal to you.

My pet peeve with the terminal at the table thing is that, despite card payment being extremely common in my area, the waiter will not bring a terminal over when you ask for the check, you'll have to wait some more.