An excellent solution is to pair daytime businesses with nighttime businesses, maximizing use of the land and especially the parking. In fact, one of the few ways to cut parking minimums without immediately causing a problem is to allow businesses with opposite hours to use the same parking. Otherwise, you have to establish alternate travel before you can reduce parking without disaster. So this is a fast solution as well as a smart one.
As for housing, some people want to live in a 24-hour zone and others definitely do not. Cities should provide housing both in busy areas and in quiet ones. Also, high-rise apartments tend to soar above the worst noise as street level. Villagescrapers with a bottom retail floor, middle office floors, and upper layers of apartments and amenities are especially well suited to city cores.