Good point! In cumulative deaths per million:
US AUS delta
2022-01-01 2477 87 2360
2022-02-01 2673 141 2532
2022-03-01 2852 204 2648
2022-04-01 2948 247 2701
I didn't look closely at the graph and I misread the recent apparent spike, which I agree with you is likely some kind of correction.I'm sorry I can't go back and edit my comment!
Only the derivative of the gap, the daily deaths per capita, has been narrowing. I agree that the daily numbers should become similar when prior immunity due to vaccination or infection becomes similar (all else being equal). But that does not erase the huge amount of deaths before people got their first vaccine.