“That gave them the room get R134/410 into place with their new patents.”
R134a has been around since the mid 30’s, so it was not a “new” refrigerant (as many believed) when it was foisted upon US in the 90’s.
The primary driver was the knuckle-headed Europeans with their constant droning of environmentalism and saving the earf. Just like the all the changes in electrical, plumbing, and other “international codes” that ended up costing people more money to abide by.
To this day, HFO1234yf is still more expensive than R12 and has substantially increased the cost to the consumer in getting their vehicles serviced with this crap refrigerant.
R12 forever, if you can find and/or afford it.
Thankfully R12 is still pretty available at places like Craigslist. You used to be able to get it on eBay but that ended earlier this year due to a change in eBay policy.