That seems a pretty gross misrepresentation of what actually happened.
The ACLU and pretty much every disabilities organization was against it.
The rule would have made it such that the Social Security Administration Flags the background check system for anybody that has set up another person to manage their social security money.
Essentially using that as a surrogate measure to label you as probably having a mental illness.
It included no due process and no evidence of correlation between having a recipient of your Social Security money and a legal requirements for getting a firearm.
One of the faults of the Obama Administration has been the use of the administrative State and the executive branch to get things like this done.
They're easily undone and don't typically have buy in politically since they were ham fisted via unelected bureaucrats.
If you want to Target mental illness and Firearms you have to first start with evidence of various correlation. Then from there you can build legally substantiated moves that won't be struck down with the court case anyways.
People made great sound bites out of no-fly no Buy. But the no fly list has no due process it would never pass Court muster. So it lost due to civil rights concerns but it would have lost anyways due to court challenges. Republican, GOPtard, etc. Senator John cornyn followed that concern with a compromise that people on the do not fly list would have a 72-hour hold on Firearms purchases and in at 72 hours law enforcement could show probable cause explaining why that person should not have a firearm. That compromise was roundly panned by the same Democrats that supported they sit in for the no fly list gun ban.
Don't make the mistake of thinking that gun safety is a single-sided issue. When compromises to move things away from the libertarian Wing are offered, Democrats don't bite either.