here in Central Europe (SK/CZ) we never done percentage, we were just rounding up the sum, like 283 to 300, but even 292 would become 300, and if it's bill 300 then tough luck for waiter. But not sure what is the situation in recent years with card payments replacing cash, tips must been hit hard, also raising prices and people going to restaurants less and less doesn't help much.
Personally I pretty much stopped going to restaurants completely during COVID when I was treated worse than dog - dogs allowed (to some places), unvaxxed not allowed to enter.
Whenever someone complains about being treated "worse than dogs" I have to wonder how they think dogs should be treated. To be fair, if dogs could catch COVID and pass it onto humans they'd likely have banned unvaccinated dogs as well.
> unvwaxxed not allowed to enter
This is the correct approach. If you are an asdhole for not caring about others but using the herd immunity znyway, this is the latest that can be done to show contempt.
My wife is immunodepressed and cannot be vaccinated. She avoids plenty of places because shit people like this do not care.
I once physically threw away someone sick and unvaccinated from a place for babies only that are not protected by the mother and too young to protect themselves. It was violent, I called the police afterwards myself.
People don't be dicks with other people life.