The EU accounts I understand have never been audited fully & published. QED
Historically, yes that was the case that the level of transparency wasn't what you'd expect.
That's changed.
https://www.eca.europa.eu/en/Pages/DocItem.aspx?did=58670"26/10/2021
A word on the ‘2020 EU audit in brief’
The ‘2020 EU audit in brief’ provides an overview of our 2020 annual reports on the EU’s general budget and the European Development Fund, in which we present our statement of assurance as to the reliability of the accounts and the legality and regularity of the transactions underlying them. It also outlines our key findings regarding revenue and the main areas of spending under the EU budget and the European Development Fund, as well as findings relating to budgetary and financial management, and follow-up of our previous recommendations.
The full texts of the reports may be found at eca.europa.eu."
Can't disagree with your take on how politicians abuse expenses though :-)