You're not wrong (with the exception of licensing schemes for some products), but the fact it's not happened before isn't a reason why it should not happen now, is it?
Why, on the other hand, should a few giant chains be given unrestricted freedom to do what they like no matter what damage they do in the process?
Btw, I never said anything about anyone having to 'get permission' to sell anything. I'm not advocating some kind of unwieldy blanket licensing scheme; just a few targeted changes to the tax and planning regimes to a) tilt the balance of advantage towards small and independent operators, and b) strip the big chains of some of their activities. That would have to involver some provision saying that X category of planning permission comes with a right to sell A, B or C type of goods. I admit, I'm not sure how that could be worked out in detail, but it'd hardly be the most complex piece of legislation ever put before Parliament.
The idea of clipping the big supermarkets' wings is hardly very new or radical. There was serious talk a few years ago of using the Competition Commission to strip them of some of their land banks and perhaps force them to sell some stores, although in the end it didn't happen. Meanwhile, plenty of countries have far stricter rules on retail than we do - I've the loss-leading bans that are in place in several European countries in mind, but there are other examples. None of this is impossible or unthinkable.
Tbh I'm getting the impression your main objection to all this is basically ideological.