There is a common gas that could be used as an almost exact pressure/gas replacement for R-12.
R-12 was commonly used in refrigerators, freezers and automobile ACs.
A gas we are all familiar with.
Of course that brings on other potential problems.
Most all the ‘new’ refrigerants are mixtures.
What that means is one component of the mixture has a different pressure/gas boiling point.
Any leak in the system requires all the refrigerant be removed, then new refrigerant added back after the leak repair.
You can’t simply add refrigerant as one component of the mixture likely leaked at a different rate than the other, changing the refrigerant percentages and capabilities of the charge.
Having just watched the technician work on my heat pump system, I can say that they have the necessary tools to do all that is required. A quite small portable vacuum pump extracts the old coolant into a container (to be emptied into a central collection tank "back at the shop" to be re-purified and reused), and then the new mixture is pumped (actually vented) in from pressurized cans. Even most R-12 and similar are recovered and recycled today. There is absolutely NO NEED for a "ban".
This is all about "continuing the momentum" of "banning things" in the name of environmental holiness. "Recover and recycle" is no longer "good enough" for the eco-nutcases.