They're getting conflated because the people who are against vaccines are referencing freedom to choose as their primary argument, as if the ability to make bad decisions implies some duty to make bad decisions.
I'm against vaccine mandates in principle, but the ultimate cause of the authoritarianism is mass media. Covid has been a fantastic setup for dog and pony shows - political hucksters rail all day about government overreach while inciting their followers to make bad choices. The large scale effects of those bad choices practically demand government intervention. And after the utilitarian system steps in to mitigate the problem, the hucksters take credit for being right about government overreach all along. It's the perfect con for the post-reality media environment - when reality asserts itself and some low level preacher dies of their own kool aid, they just go silent and are replaced by another ignorant voice on the same channel.
If we had a level of societal trust such that you could expect that most everyone would be taking measures to prevent spreading Covid, then coming together in large groups (eg employment) would be less of an issue. But as it stands, why would anybody want to go back into the office when it's likely that at least a third of your coworkers will blithely get you sick? And hence OSHA et al step in, using the same rationale as when preventing operating heavy equipment while drunk - it creates an unsafe work environment.