I support people working cooperatively to do whatever they can to mitigate the social impacts of the virus. Just because it didn't prevent the spread didn't mean that it didn't help mitigate symptoms. Maybe instead of putting a bunch of obese Americans in the hospital, the vaccine helped them only miss a week or so of work... therefore lessening the strain on our medical system, and increasing economic productivity. It is to society's benefit to have healthy people.
It doesn't HAVE to stop the spread to be a reasonable thing to do. Hypothetical: What if China had used the conditions as to their advantage and invaded Taiwan? Do you want a bunch of your potential servicemen to be at risk of severe (even if non-deadly) symptoms? Do you want your economy to lag because of the disease effecting factories' agility to build planes, tanks, and munitions?
Finally, I also see history where there were large scale riots throughout the 13 colonies about vaccines & inoculation for generations....even though they worked.... there were still stupid people that thought they should have the right to be stupid, and that their independence was more important than the prosperity of their communities. I don't support the thoughts of those people. I support the thoughts of Washington, Jefferson, Adams, etc... who believed vaccines were to society's benefit and who imposed mandates and promoted them. In fact, I would argue that other than independence from the crown.... vaccines were one of the few things that many of the noteable founding fathers agreed upon.