Every $1 invested in the IRS generates a $5-$9 return per the nonpartisan CBO https://www.cbo.gov/publication/57444

The Effects of Increased Funding for the IRS

CBO estimates that portions of the Administration’s proposal to increase funding for the IRS by $80 billion over the 2022–2031 period would increase revenues by approximately $200 billion over those 10 years.

Which is why our nation's pretend-conservative party wants to tie vital foreign aid to offsetting cuts to the IRS budget.

But that return mostly comes from upper and upper-middle class folks, i.e. where the money is, and where it's not just salaries/wages that are on a W2 so there's more to dispute about. If it all came from poor people the GOP would be fine with it.