I lived in Westminster for years, in Fitzrovia, and it was quiet at night, even more so once the buses stopped running. Even the pub on the opposite side of the road from my flat closed at 11.
At weekends it was blissfully quiet until I walked the 5 minutes down towards Upper Regent Street from Portland Place. It was all firmly residential, full of big mansion blocks of flats, with only a few local shops and one slightly bigger Europa supermarket. Marylebone was like a village.
Antisocial noise is just that even if it’s in a city centre. In a residential area, which that area is, people should have every expectation of a good night’s sleep.
Oxford Street is no longer any sort of premium shopping street so if it can become somewhere more pleasant to visit I’m all for it. The odd times it was closed in my day were wonderful. And I knew it well as I walked part of it to Bond Street for work every day.