Changing refrigerants and propellants away from fluorine chemistry and installing desulfurization equipment on coal plants are both many orders of magnitude easier than reducing the amount of hydrocarbons we burn globally to the point where the temperature increasing is stopped or reversed.

One of them requires the entire global population cooperate to burn fewer hydrocarbons. The examples you mentioned were handled in the US by regulating power plant operators and chemical manufacturers.

Both of those problems you cited are far smaller and easier to fix than the ~1,500 gigatons of C02 humans have emitted in the past century. CFC's have a half life of only 50 years, C02 just persists now forever since we're dumping it faster than can be consumed. Acid rain was a mostly localized problem, not one spanning the entire Earth and affecting ocean temps, ocean currents, etc etc. The cited problems are insanely easy to solve compared to global climate change.

It's likely / probably unsolvable at this point as we're hitting tipping points for which there is no effective return such as permafrost melting and releasing more co2, causing more heating, melting more co2, etc and partial shutdowns of critical ocean currents. But yeah I know...MUH FREEDOM.

You can look up the carbon cycle on Wikipedia, it is fairly well understood where atmospheric carbon can go. Most processes that sequester carbon long term take geological time spans. So unless you think we engineer sequestration at a rate comparable to what we emit today, atmospheric carbon is here to stay for a really long time. Personally I think we won’t be able to scale sequestration technology sufficiently in the next decades to make a dent in the carbon levels.