Has it really decreased the prevalence of acid rain that much, and was acid rain really that large an issue? I haven't heard anything about it since the 90s.
If you're in the West then you haven't heard about it much because it really was a big problem and reducing it was a success story: "Wet sulfate deposition – a common indicator of acid rain – dropped by more than 70% between 1989-1991 and 2020-2022." https://www.epa.gov/acidrain/acid-rain-program-results
I think you've demonstrated how forgetful we are. A problem gets solved but because it's not a problem we question if the fuss was worth it. Same with the Y2K bug, that got loads of hype and afterwards people complained that no planes fell out of the sky, ignoring the massive amount of work that went into reducing the problem.
Yes. Though the Y2K bug was 'only' ever going to affect boring backend operations, not planes falling out of the sky (nor nukes going off..)
I put 'only' in scare quotes, because that would have still been enough chaos and disruption.
(Compare to how Covid was/is by and large a fairly harmless and mild disease and only really poses any danger, if you have pre-existing issues or supremely bad luck (just like lots of diseases we already have), but still managed to paralyse society.)
Coming back from the tangent: in the West sulfur emissions were tamed with a cap-and-trade regime (if I remember right), which is a pretty good example that these things can work, if implemented and enforced properly. Alas, so far similar efforts for CO2 have been lacking.
