If you make driving more frustrating and less convenient, it can make the other options relatively better in comparison and people may take them. It can also generate demand/political will for other transit modes that may not exist if driving everywhere just works fine for most people.

I'm not saying that's their plan, but on the scale of like 2-3 decades it's not preposterous that making driving worse now helps eventually. Certainly it's not worse than widening roads, something that at this point is well understood to not actually help.