If someone wants to drive and do things by car, why wouuld they go to a town center, seriously?
Even if towns go out of their way to "try" to make town centers as car-friendly as possible, they are at best going to be a poor-imitation second-best to shopping centers, in terms of car friendliness.
Out-of-town shopping centers inherently have far more space, because of their locations; this means that they will always be able to beat town centers in terms of offering free, easy parking and massive roads that don't get clogged with traffic, and they also have enough space to create pedestrian-only spaces inside, where shoppers are shielded from the cars.
So, I can either crawl through busy traffic and fight for a parking space at a town center (there will literally never be enough, no matter what town centers do) and then spend my shopping-time being assaulted by car fumes, car engine noise, and anxiously plucking my child out of the way of vehicles....
....Or, I can simply drive to an out of town shopping center, enabling me to proceed smoothly along spacious roads, park easily with tons of extra space, and then have a nice car-free shopping experience indoors where my child can run freely?
Who in their right mind is ever going to choose the first option?
I think we should allow urban areas to be urban, and allow suburban/rural areas to be surburban/rural.
Fill city centers up with loads of housing (townhouses and apartments), the way you see in Tokyo or Barcelona; keep the cars (mostly) out, and have town centers as nice minimal-traffic places where people can enjoy the urban experience of wandering on foot and people-watching as they shop and get lunches and coffees.
For those who want to drive, or perhaps find it hard not to go places by car because they have mobility issues which make walking tough but don't stop them from driving safely, out-of-town shopping centers should be maintained and are the perfect shopping solution for those who want or need a more car-centric lifestyle.
Right now, the UK urgently needs to build shitloads of housing. Understandably, there is reluctance to build on green fields and meadows. But if you are going to focus on building lots of housing on brownfield sites in-town, we need to accept that the cars need to be heavily restricted in these builtup areas, because it isn't fair to expect people to live in a traffic thoroughfare for suburbanites' cars, and all these people packed into city centers are not going to be able to own their own cars in the majority of cases as there simply will not be room.