Did Covid structurally change US airline traffic?

That the pandemic did a number on the US travel industry is not in question.  The US travel industry has been hit before on 9/11.  But nothing like the Covid pandemic had this long an impact.  Take a look at the chart.

An odd relationship in 2019 seems to have broken in 2020. We use January 1st, 2019, as the base point equal to 100 for both curves.  Then, we track the base number daily over the timeframe.