I’ll add a 6th reason revenue is down: in 2021=22, Bitcoin went down 300% and any number of people lost their fannies on it. Since the IRS began demanding to know all crypto transactions, thinking they’d catch people making previously untaxed money, a funny thing happened: all those tax sugarplums turned into tax write-offs, spaced over years ($3K/year until the loss is fully written off).
That adds up. Correction: that subtracts down.
#7
A percentage of people, mainly wealthy retired people, have structured their savings to avoid taxable income.
My wife and I have no earned income. We cost the Treasury money.