How about: US citizens saved $34B by not having to stay in the highest COL areas? Why should we sympathize with a minority of rent-seekers?
But the underlying paper makes it clear that it's the former. So it's not accurate to say "US citizens saved $34B...". That was their aggregate income, which is still subject to the same federal taxes no matter where in the US they moved. They would have saved on state and local taxes, depending on the rates of their new home jurisdictions.