Sorry mate it appears we have a different perspective on what is HUGE and proportion. This happens a lot with words.
HUGE problems to me are not fixed by agreements to decrease sulphur dioxide omissions and agreements to phase out chemicals. A HUGE problem to me is something that you cant agree away and something that you cant control.
Its all perspective and proportion I guess.
As I see it, a huge problem is something that has huge consequences unless solved, and that solving the problem is difficult. Maybe it seems like child's play now, but it's not easy making the whole world agree to something. The reason they were able to agree on solving those problems so quickly back then was because the consequences were so serious.
NASA made an interesting study where they simulated what would have happened if the world had not banned CFCs. They predicted that the ozone layer would have gotten thinner and thinner until around 2050. Then it would have collapsed completely. In 2065, you'd get more UV radiation by stepping outside than when inside a tanning bed today. Turning the world into a giant solarium would have been a huge problem, I think. But we thankfully avoided that, because world leaders stepped up and took responsibility for once.
Here's the study if anyone's interested:
https://www.nasa.gov/topics/earth/features/world_avoided.html