You're right, the vaccines don't have 100% efficacy. However, they are the only way out of the pandemic (so that we can safely transition to an endemic state, much like the flu--still annoying and sometimes lethal, but not mandating the current constraints).

There are quite a few people who aren't getting vaccinated because they have doubts AND because they feel healthy and do not think they are at risk of a severe course of COVID-19 infection.

If their physician could tell them with confidence that the virus is very likely dangerous to them, that would maybe push them to getting vaccinated despite their doubts.

This stuff is hard. There are people that simply won't be convinced, no matter what. But anything to help sway the more reasonable "skeptics" out there is a win, I think.