They have had wireless chip readers for years, but many restaurants still take your card anyway. Some places bring the payment device to you, which is nice, and some have it there always so you can see exactly what's on the bill (sometimes you order on it too).

But taking the card is a cultural thing, not a tech thing. Even back before wireless readers were a thing, they still had portable payment terminals and could have you swipe there or have you pay up front on the way out. It's not an issue at all.