For an individual it is a formula of should_vaccinate = (risk_of_getting_covid_19 * bad_outcomes) - (bad_outcomes_from_vaccines + risk_of_getting_covid_19_after_vaccine * bad_outcomes_of_covid_19_after_vaccine) > 0
On the group level you would have to consider the damage on the group level as well from not getting vaccinated due to increase of covid-19 spread, and increased hospitalisation levels.
On the global communication and messaging level I agree you should tell everyone to vaccinate as you can't easily provide everyone with those calculators. And not to mention people not being able to come up with correct values for those factors themselves.
However, pretty much any real world person doing those calculations and arriving at the conclusion that they're better off not getting the vaccine is engaging in motivated rationalization rather than reasoning. Almost no one is actually living as a hermit, unlikely to ever be exposed to covid. And just about everyone who will be exposed will be safer having had the vaccine, considering all the risks and probabilities you listed.
1. Age. Not all age groups were recommended the vaccine.
2. Last time or where you have had Covid-19 at all.
3. General pattern of activity and the amount of contacts with other people.
4. Last time you have had the vaccine.
E.g. in my country through it's technical systems didn't allow you to get a Covid-19 vaccine when you had the virus within last 6 months. While US recommended the vaccine much shorter period of time after having had Covid-19.
> Almost no one is actually living as a hermit
Also consider that in 2021, there were actually many people living as hermits, including I, as I really didn't want to get the virus. At the time I was terrified of getting it. In 2020-2021, I did live with my partner, but we worked remotely, worked out outside away from other people and we did cardio/gym, but with home made equipment or outside keeping distance to other people.
