The IRS never stopped going after middle and working class tax cheats. They stopped going after the very rich because their budget was cut to the bone and they couldn’t afford to fight a protracted lawsuit and possibly lose.

The reason they’re going after them now is because funding the IRS, at least on paper, brings in more revenue. So, it was a way for the Senate to get the Inflation Reduction Act fully paid for without adding debt or changing tax rates. (Same with allowing Medicaid/Medicare negotiate prescription drug prices. There’s a lot of money in America’s couch cushions.)