I would say tipping for served or delivered food, isn't even always expected, or at least it wasn't until say after 2020. If you have good service/food you might have left 10%, or just throw a few extra quid/£5 on the table after playing the bill. With large group yes it was expected. Now as we have moved cashless it is getting common for restaurants to add 10% to 15% to the bill as a service charge. Not used JustEat or Uber Eats, normally just order direct, and drivers for the local Indian or Dominos, don't seem to expect a tip and I've never given one.
Back when I was getting taxis, it was usually just keep the change (rounding to the nearest £1, no idea what it is like in the cashless society we live in now.