I don't know if it will really make any difference at all. Many people consume alcohol regularly and we already know that it's bad for you. I think most people are willing to make tradeoffs, especially when in moderation the negatives aren't really that big.
I doubt most recreational users are using it at anywhere near the same strength or with the same frequency, however.
We're talking the difference between 2 and 200 milligram doses of THC here in terms of how it affects people on these levels. One comes in a soda at the store down the street from me. The other you can't get like that and might send your average recreational user to the hospital with a panic attack.
I'm wondering also if one of the big factors here is oxygen deprivation. These sound kind of like the same kind of numbers of cognitive decline that you see in air pollution, maybe just generally clogging your lungs with smoke could be comparable.
With the legalization in a lot of states people are consuming ridiculously strong amounts of THC these days and it’s only getting legalized in more places.