Pretty egregious over-simplification, rife with loosely connected vagueries.

This is an issue of debt providers being willing to underwrite just about anything due to the flood of capital that needs to be deployed, not one of m&a being evil (no matter how often you randomly invoke Enron and WorldCom). This is an issue as, or more, prevalent in the public markets. Any forthcoming IPOs come to mind?

Second - quality of earnings and financial due diligence is performed on the buy side as well as the sell side. Accepting addbacks comes down to the buyer and their lenders discretion.

Third - if synergies don’t cone to fruition then that DOES impact a firms compliance with their debt covenants.

The problem here is oversupply of capital and loose underwriting. It is lazy and irresponsible to invoke Enron and WorldCom comparisons, boiling down PE playbooks to “accounting shenanigans and over leveraging”.... is multiple arbitrage not a real thing? What about the many platforms built around their bench of operating executives? Are more deals not going to long term private capital, which uses less leverage than traditional PE?