Cash still?
Card payment terminals?
Ps the center of Venice is a terrible theme park. But if you walk towards the edges you can still find some great more original areas.
Around St Mark's square though it's an endless row of tourist shops all selling the same souvenirs, handbags and masks all operated by Chinese. I hardly saw any original stores there.
Nothing against the Chinese but obviously you go there to see Italian culture. Not to buy cheap imported knick-knacks. It seems like they're all the same franchise or something. The same bags all displayed in exactly the same way in copy pasted shops. IMO there's nothing genuine left in that area. It's just another Disneyland. The McDonald's of tourism.
We did find some quiet original areas farther from the tourist zones (which is basically the strip through the middle from the station through the Rialto to St Mark's). We found some original shops owned by old Italian people and a really quiet square where we spoke to a priest closing up his church (who was super nice). We sat there watching the night set in and it was quiet and beautiful. That night was really the only time where I felt any of that Venice magic. The rest was just exhausting and obligatory industrial tourism.
The tourist areas made me deeply sad. I live in Barcelona so I know what mass tourism looks like. But even the most touristy spot here (the ramblas) is not nearly as thoroughly destroyed as Venice is.
Oh and of course don't eat anywhere they have pictures of the food posted outside and these guys trying to convince you to come in.