Not trying to be too sarcastic. Some people want to take the test just to convince themselves they are (or are not) sick or need the affirmation.
I asked my doctor if I should get antibody tested. I dont think I have been sick, though my wife might have in Feb 2020. She had a high fever that lasted two days them all was well. She was never tested either. So we dont know if we were exposed or not. I have treated it as if we were not. Anyway, the doc says it wouldnt do any good to test because they dont even know what level of antibodies is effective against the unknown level of viral load you may become exposed to.
The recommendation to take the vax results from the risk of contracting a serious case of COVID19 being worse than the risk of a vax side effect. So its a risk analysis. Each person should make their own decision regarding the risk they want to take.