Do the food app delivery people get to see the tip amount beforehand? If the tip is not enough, do they decide not to accept the task? I've had several Uber Eat

Do the food app delivery people get to see the tip amount beforehand? If the tip is not enough, do they decide not to accept the task? I've had several Uber Eats where my food arrived late, ice-cold, and wrong order. I've stopped using those services.