The trouble is the choice not to wear a mask in a time when thousands of people are being treated for what is a life-threatening disease, and many hundreds are dying imposes upon other people.

Freedom of choice to do things that do not damage other people is our right. But, to quote Abraham Lincoln (among others) "My right to swing my fist ends where your nose begins."

Even aside from the small, but still real danger of infecting others (even in the case where we are properly vaccinated and recently tested), not wearing a mask in a crowded tube train is liable to make some people feel threatened, and it also serves to encourage others to choose to discard their marks. Anti-social behaviour is infectious.

There is no equivalence in such circumstances between choosing to wear a mask, and choosing not to wear a mask. The former has no potential to cause harm to other people.