I am thankful for insurance but the ACA has allowed the system to overcharge older independent rate payers to subsidize others.
Not exactly sure where you got this.
The ACA limits the premiums for older individuals to no more than 3x the premiums for younger folks. That's lower than was the norm pre-ACA, and lower than alternative proposals at the time. It was a compromise at the time the law was enacted.
Certainly older folks pay "more". But to characterize that as an "overcharge" and a "subsidy" for others indicates a lack of understanding of how health insurance works and who uses the benefits of health insurance more.