When the IRS is underfunded they unable to expend the funds needed to tackle complex audits. Who has complex audits? The wealthy 1. 100M & billionaires 2. multi-national corporations 3. venture capital tax schemes.
According to the CBO: https://www.cbo.gov/publication/56467
"CBO estimates that increasing the IRS’s funding for examinations and collections by $20 billion over 10 years would increase revenues by $61 billion and that increasing such funding by $40 billion over 10 years would increase revenues by $103 billion."
Additionally the poor are now being audited as much as the rich (but not the super rich). Maybe this could be seen as IRS incompetence but I think given proper funding and motivation they'd be happy to turn this around. The decline of the auditing of the wealthy went hand in hand with IRS de-funding.
"Americans who receive the earned income tax credit, one of the country’s largest anti-poverty programs, are audited at a higher rate than all but the richest taxpayers. "
https://www.propublica.org/article/irs-now-audits-poor-ameri...