It isn't the wait that is the problem for me. (It would just be a boring inconvenience.) For quite a number of blood tests, time matters.
Our local hospital phlebotomy opens at 08:00 which, with luck, means a draw just early enough. The GP appointments don't even start before 09:00.
Time wouldn't be quite such an issue if the medics even realised the importance of time of draw. They don't. So they don't, actually can't, make any allowance. Diagnosis, adjustments to medication, etc., can all be affected because of this desperate ignorance. (Yes - there is recognition of time for some tests.) Nor do they recognise that far more tests are affected by fasting/not fasting than is ever acknowledged.