Even during a "good" year, though, the number is still around half. (Recall Romney's "47%".)

That's true, but (especially when spread by politicians) terribly spun.

Almost half of americans have no federal "income tax" liability. They still pay a ton of federal tax on every paycheck they receive. Their income is absolutely taxed.

That's just not true. It might be taxed at the state or local level, but a lot of people simply don't pay federal income tax (and in fact receive a relatively large refund at the end of the year).

(many people get confused and interpret social security and health insurance withholdings as taxes).

Many people refer to payroll taxes as payroll taxes, yes.

Especially since they are, literally, taxes.

I would probably even go so far as to call insurance a tax as well since I am legally required to pay it. I may have my choice what company administers my policy but they're effectively private arms of the government.

There's no federal tax penalty anymore as part of trumps tax cut. Some states are enacting state tax penalties now though

It will definitely reflect what you see this year, and probably a few years to come. It hasn't gone away, international travel is not the same (changing who is available to work due to reduced emigration), supply chain disruptions and reconfigurations continue. The workforce has changed, too, wealth inequality is now on the forefront of many people's minds, remote work is more prevalent than ever, and it has changed how people are engaging with work.

We do not know that COVID impacts are "transitory". It is only by assertion, by people who I would say have all the motivation in the world to claim they are "transitory". At the moment I can't provide any evidence that they are "transitory" beyond the bald assertion. They can just as easily be permanent.

We won't know for at least another five years at a minimum.