I got to the L.A. area in 1982 for college and the air was orange. It was difficult to breathe while walking around campus all day and it was actually painful. Over the years the air got cleaner, is no longer orange and it's not painful or laborious to breathe. Yes, when stuck in traffic for a couple of hours and you're sucking in the emissions around you it's not so great. Otherwise, the clean air is very much appreciated.
If you can build a time machine, go back to the L.A. of the 60s, 70s and 80s and tell me you'd genuinely rather breathe that crap and have a slightly larger intercooler then go right ahead. But, having lived through it I'd say I'd much rather have my much-faster-than-all-those-old-cars stock '18 R and clean air. Yeah, some of the items the CARB picks on are stupid and likely not effective at all in keeping the air clean but you can't tell me stock cars are not fast enough today and require pollution to be "fun". I'd rather breathe clean air.