I'll speak to this personally. In April 2021 New York City raised its top tax rates. I'm only moderately wealthy, but that prompted my moving out of the state.
> is an even better argument for universal pensions (which isn't Social Security, as was never meant to be treated as a pension to begin with)
That's one option. Another is better distributing productive capital. Building public housing so its occupants wind up owning it, for instance.
But that's getting into top-down redistribution at the federal level, which isn't in the cards for now. Within the context of cities and states, pensions are no longer a good idea.
Morally, they shouldn’t. But practically: because old people vote—en masse and consistently, and young people don’t. Until that changes, our systems will continue to be designed to transfer wealth from the young to the old.