Regardless, you have to make cities a desirable and affordable place to live for this to work at scale. You can’t just fix it at the transportation infrastructure level.
If I’m looking for affordability, low violent crime, and good schools, I am not looking anywhere in the city where I live. It didn’t used to be this way, but post-covid housing costs are so high that I have to go 40+ minutes out of the city to get those things. If you don’t change that, many people with families are just going to deal with traffic being worse rather than moving into the city.