Lighter construction to lower shipping costs, mostly.

The newer coolants also require higher pressures to function, which puts more stress on the components.

R-12 didn't put any holes in the ozone, it's just that a good R-12 system can function for so long that it's not profitable. There's a long story about how the hole in he ozone layer story was foisted on the public. We how have less effective aerosols that are way more expensive and systems that aren't as reliable, intentionally. 🙄