You will still need shops, and they will still need stocking up. That means delivery access. Larger delivery vehicles are a lot more efficient, and so less are needed. You likely will always want a controlled way to get transit sized vans in and out. I would rather that was planned in, in a controlled manner, rather than left to big business, or bodge jobs. E.g. by back delivery roads. Underground would be perfect, but generally isn’t viable.
You also need access for construction and maintenance.
Unfortunately, these requirements also make a vehicle centric model easy for cities, and so, by extension, car centric. Many places default to this. Finding a viable solution requires getting a balance (enough road access to keep places supplied, but good enough support and incentives to keep unnecessary cars out).