What do you mean by that phrase? Why would saying that there should be at least a certain amount of amenities within walking distance for certain new developments affect the route taken to get somewhere else?
Because the only way planners have to make 15 minute cities is to make long distance journeys as hard as possible to force people to rely on the poor quality services near to them.
Planners can decree that amenities will open, but they can't actually make them do so.
15 minute cities are based upon the assumption that the population can support a high density of shops, services etc such that they can be spread around so that everyone can be within 15 minutes of them.
With escalating labour costs, I find it extremely doubtful this can really be true for a wide range of services without driving densities into the range associated with the Kowloon Walled City.
The entire concept is based around the idea of a huge supply of cheap labour that can be used to staff all these shops and other services, and it simply doesn't exist in the UK and hasn't in decades.
What will actually happen is a handful of overpriced corner shops will be the only game in town, which people will only use when "traffic filters" et al are used to restrict travel to destinations further afield.
EDIT:
To clarify, in essence the large distant supermarket model won because it is more staff efficient and can offer a far superior retail experience, especially in an environment with high labour costs.
The same is true for a bunch of other services and amenities. The only way to reverse this trend is to use "regulation" to destroy the experience of using these places such that the markedly inferior local option becomes preferable.