vaccines, there has never been a severe side effect emerge after six months of use...typically the limit is closer to six weeks. Also, there have been over 600 Million doses given in the U.S. and over 12 Billion throughout the world...no need to worry about "the future"....oh, and the side effects we have are extremely rare.
Next, there is no vaccine mandate...no one is being forced to get a shot...but since the vaccines are incredibly safe and effective at keeping people from being hospitalized or worse, and there are always people who don't realize they have risk factors...it's sensible to recommend that everyone in tested/approved age groups get vaccinated and boosted...plus, there's no cost to them.
Note that preliminary data on the new bi-valent booster shows a marked increase in protection against infection from the prevailing variants (see link below), so you should adjust your perception accordingly.
https://www.statnews.com/2022/11/22/data-show-updated-covid-19-boosters-increase-protection-against-infection/
This whole issue is super simple...when it comes to avoiding severe illness or death, getting vaccinated and boosted works way better than the alternative.
Link: https://www.cedars-sinai.org/blog/why-vaccine-boosters.html