There's certainly room to debate how the IRS is spending its money, but they've spent some of it on responding to taxpayer questions, resulting in a decrease in wait times and other improvements: https://home.treasury.gov/news/press-releases/jy1421. These are their own metrics, so it's possible they're being gamed in some way, but it's not true no money is going toward helping taxpayers.

Not quite. Of the $79B, $46B was earmarked tax law enforcement, while $4.8B is designated tax processing modernization, including a plan to replace the current legacy systems (IMF and others that are written in a combination of COBOL and assembly language and that run on 1960s mainframes against IBM VSAM data files, and which the IRS have been trying to replace since the 1990s) by 2028. That money is supposed to be spent that way, and the IRS have to get approval from Congress' House and Senate Appropriations Committee (and TIGTA, Office of Management and Budget, and GAO must all sign off on each request) for all their expenses.

I won't disagree that their IT woes seem to be in large part due to incompetence, however.