I assumed it was part of a COVID precaution reduced service standard. So instead of an FA walking down the aisle with a tray of water cups (or little bottles/boxes) instead you had many passengers make their way to the back of the cabin to get something to drink, passing each other in the aisle etc./squeezing by the lav line And of course the risk of distributing credit card apps is probably not significantly different from the risk of handing out water bottles. I didn’t hear any call button dings near me, and I don’t generally use it. If I am in an aisle seat, I prefer to get up and walk to the galley in the back. Seems more… polite .. and efficient.