Personally I think it should be perfectly acceptable to provide a serology test that shows you had Covid in lieu of a vaccination.

That is a statement about the past: "I am immune and here's proof. (either by vaccination or serology test)"

What we do about the future to contain the pandemic is separate question. If you're not a immune you should get a vaccine now.

That is the statement about the future: "I will get vaccinated, because I am not yet immune."

In an ideal world we'd be done here. Together these two statements make perfect sense to me.

Unfortunately there is some inexplicable (again, to me) resistance to getting the vaccine in some people. And hence it is not wise to end here.