Common, I don’t know which words you don’t understand as you reply in generalities: those who were not careful increased propagation of COVID and contributed to 600K people in US dying. If you are meikel on that, you should expect less respect that people who are meikel on shabbos or kashrus.
As you did, I was going back to one shul last June, measured their air flows, opened windows. Then, half of the minyan would close windows and wear masks half-way despite (Lakewood-type) Rabbi’s instructions. When an elderly person came in and they continued the same way, I just did not see myself davening with a group like that.
PS The fact that I was instructed [by my wife] to wear a mask (on a plane) in mid-February, while CDC and common saychel decided in mid-March, was a proof who I should listen to :). Mi hu hahama – roa es hanolad.