So, . . ah, can have our r12 back now (a perfectly safe & useful inert product, it's inventor breathed it in & blew out a candle with it half a century ago).
Nothing better has been or will be invented, 134a is an older more dangerous formula that doesn't even work as good.
Forcing use of 134A was just a way of generating new income for a certain corporation by making everyone buy a new (old) refrigerant.
Hey, if it was up to me.....