London

You are right that they can't compete directly with online shopping, but that's not why people go there. Studies have consistently shown that closing shopping areas to through-traffic is good for businesses, precisely because it makes them easier, not harder, to access. Shops don't benefit in any way from hundreds of cars (or, in this case, buses and taxis) driving past them!

EDIT: Thought I should link to a specific study rather than just vaguely waving at them. There are many to choose from but this one is particularly interesting because it's from the US, where they generally don't have good cycling and public transport infrastructure, but it still shows benefits for businesses:

While we observed some mixed results, we generally found that street improvements have either positive impacts on corridor economic and business performance or non-significant impacts.

It's important to note that nothing always works everywhere ('some mixed results', here), but the balance of evidence is in favour of at least trialling traffic reduction schemes in commercial districts.