Now, whatever you want to believe the cold, hard facts are that what federal employees who retire finally draw out of their retirement system is fairly much equal to what they contributed out of their after tax salaries to that system.
You can believe Uncle Sam is making this contribution, and that contribution, and hey, look at those bucks over there, but even if they are "credited" to the FERS or CSRS systems, unless they are ever paid out they never really existed.
Then they die ~ and all the money they contributed to the system stays right there. Federal retirement money is NOT inheritable. You can't hand it down to your heirs. When you are gone it stays in the system to be used by other retirees at a later time.
In recent years USPS was charged about double for its retirement contribution needed to make OPMs books balance. The amount overcharged went up to $80 billion according to some estimates, but was, even as OPM admitted, well over $30 bilion.
Remembering that all the USPS funds were coming out of postage paid to send mail, or directly from employee after tax salaries, and none of it came from the taxpayers, you'd think Congress and OPM would have made an "adjustment" such that the employees had their excess contributions returned to them, or retiree payments were increased, or postage rates would be adjusted downward in appropriate categories to kind of "sop up" the excess.
No, Congress passed a law that handed that overcharge to OPM as "found money". It's being paid out to ordinary federal government retirees now, not kept for later use by postal retirees. Plus, Congress decided USPS should be punished for OPM's computational error by paying $5 billion per year IN ADVANCE for future postal retiree medical insurance.
This happens every time someone finds a mistake in the system that's in the favor of the employees ~ Congress simply keeps the money!
You are mistaken about the source of funds. An employer pays the total cost of compensation including salary, fringe benefits, and retirement. Government mandates may impose additional costs on the employer (such as payroll taxes) and reduce the take home salary of employees. The ultimate source of all contributions to retirement is the employer although your salary is restricted a little for a contribution.
You are also mistaken that the contributions (both employer and employee) are equal to the amount of deferred compensation provided by the FERS plan. I have just finished analyzing a plan very similar to FERS. The Florida Retirement System (FRS) provides the same benefit level (1%) with retirement beginning at age 55. FRS does not provide the early Social Security benefits. The FRS COLA (automatic 3%) is lower than the FERS COLA. My analysis indicates that the average surplus deferred compensation (value of retirement benefits beyond account balance (contributions compounded at a conservative interest rate) is more than $200,000. The surplus deferred compensation is much higher for professional and administrative employees with more opportunity to manipulate salary in their later years.
State retirement plans are funded while federal retirement plans are unfunded. There is no portfolio funding your benefits. Congress has already spent all money contributed to your retirement. Future taxpayers are entirely responsible. Any contributions made to your retirement are worthless for funding future benefits. The bookkeeping does not matter.
You are arguing for additional compensation. The USPS contributions are funded by consumers and taxpayers. Employees are not funding anything. You are trying to obtain additional compensation at the expense of taxpayers and consumers.