So all-in-all killing this 15 minute wait might not be very effective to quicken vaccination, but it should not be harmful at all either, so no biggie really.
I took both Pfizer shots already and I had to wait 15 minutes only after getting the second dose.
I really appreciate the hard work of our health professionals, but I think most people didn’t wait after the jab because we are not following the vaccination protocol as we should.
People just don't talk about them. They happen, with a much lower (by orders of magnitude) rate than the ones caused by the disease, and AFAIK not distinguishable from the random average without a vaccine (what is very surprising, so I probably have bad data).
Anti-vaxxers do make a big deal about them. But people are very good on ignoring the fact that everybody has a small chance of just dropping dead at any time by random, so most people just don't listen.
Anecdotal I know, but it really was a case of waiting around for people to leave before they could continue.