Those things are atomic.

CFC’s are great at coolimg things as long as you do not care about having an ozone layer.

They're even fine if you care about the ozone layer so long as you never ever let any leak. Until the coolant leaks the CFCs are cycling in a closed system in which they can't do any damage. The problem is that "not letting any leak" is harder than it sounds, and the newer coolants just don't do the job as well.

It's like how asbestos tiles are fine until they get damaged, and then they fuck the lungs of anyone unfortunate enough to breathe in a tiny bit of it.

Here's the thing. CFCs were used until the manufacturers could patent the next harmful chemical to keep the profits. The replacements are also bad, it turns out. Just like how all that "BPA plastic" hubub ended up with "BPA-free plastic" that was literally just another synthetic estrogen. Same problem, but it isn't BPA so people thought the problem was solved.

CFCs:

• Bad

HCFCs:

• Slightly less bad, but: HCFCs still have some ozone depletion potential (ODP) and are being phased out under the Montreal Protocol.

HFCs:

• HFCs do not contain chlorine, so they have zero ozone depletion potential (ODP).
• They are potent greenhouse gases with high global warming potential (GWP), leading to further phase-outs under the Kigali Amendment to the Montreal Protocol.

Now they're shooting for:

• hydrofluoroolefins (HFOs) and natural refrigerants (like CO₂, ammonia, and hydrocarbons).

Reality is, the trope with old cooling machines being so much better than newer ones is that they didn't care about "efficiency" when designing them and the machines just ground their compressors to death getting the job done.

New AC units use modulated power to the motors, multiple cooling stages, and other "efficiency" features to make them more energy-efficient, start more gently, and run "better" on paper (although the added complexity, as statistical analysis will show, also adds to more reasons for the machines to fail.)

I actually recently begrudgingly went from a 20 year old "last of the CFCs" type AC unit to a modern one using one of the newer-but-eventually-will-be-banned refrigerants. Didn't want to give it up, for the trope. When all said and done, I went from a 12F degree temp differential across the old unit to 24F on the new unit. (Input temp drops by X degrees on output.)

And the CFCs were safely bottled up from the system when replaced (although they likely made a hefty profit on the stuff since it is banned but can be reused in the US.)

I thought that was over