Fellow Brit here and I mostly agree with this assessment.
> The irony that every local council in England talks about 'saving the high street', without the self awareness that they caused the problem, and are still causing it.
I'm not one to stick up for local councils (pretty much ever) but I think the writing was on the wall regardless of what they did. You're right that they started the demise of the town centre with everything you've outlined, but frankly the internet was the tidal wave that shortly followed and it really wouldn't have cared too much what local councils had done or not done. This shakeup was going to happen one way or another anyway.
As we progress forwards, everything trends towards being commoditised. We automate, scale up, and what was once specialised is now general.
The supply and retailing of goods used to be a much more specialised endeavour. Just owning a business (eg. small highstreet shop) which sourced goods from disparate suppliers and made those goods available for you to browse and purchase used to be a more specialist/niche pursuit. That's no longer the case. Almost all retail has been fully commoditised now, and retailers (particularly small shops in town centres) can no longer survive if they just think of themselves as "retailers". These businesses need to think "what is it that we provide to customers, _other_ than our physical goods?" And if you're in a competitive area (eg. book sales) - is the value that you're adding, on top of the baseline service of "commodity retail of books" enough to differentiate you from your competitors, both online and off?
The mistake that some of the larger retailers have made, is that they've seen the efficiency benefits and economies of scale, and the commoditisation of their industry, and taken advantage of them aggressively, without realising that by doing so, they were slowly eating their own business model.
I imagine that, in the panic of trying to compete with online retailers, a lot of big department stores have focussed too much on cutting costs and streamlining (in order to offset their rapidly falling profits) and not enough on actually changing/updating their model to add value to the customer experience in ways that online retailers cannot.
A business like John Lewis needs to decide if they're in the commodities business or the customer experience business. If the former, then fine, outsource away, mass produce, cut your staff training costs, but then all you have is your baseline retail, which means you have to compete with EVERYONE else that sells the same things, and a chunk of those people just sell them online, without the overhead of physical stores.
If you're in the "customer experience" business (which arguably any business that has a physical presence is to some degree), then you need to be very careful about the things you choose to streamline and cut costs on. Staff training and retention needs more focus. Additional value-add services need more focus (and not just bullshit low hanging fruit psuedo value-add, like "extended warranties"). The design of the physical environment itself needs more focus.
There is a way to get people back into town centres. It does (in the UK at least) require some focus on infrastructure but it also needs the businesses that populate those town centres to become very clear about what their priorities need to be in order to attract customers and to provide something that their online counterparts can't.
As a side-note, Apple stores have done particularly well over the years partly because the experience you get in them (and it's admittedly not always good) is totally unique. You literally cannot go to any other place on earth and get the same experience and service that you get from an Apple store. Now it's a bit of an unfair comparison to small high-street retailers - Apple have an advantage because they have such a tight control over their retail experience and their service/repair options (don't want to get into that debate) but the fact remains that Apple stores consistently still draw massive footfall because there are very specific and unique reasons for customers to go there. And they invest, heavily, in the training of their retail staff, the physical environment, and provide high value in-store services that are demonstrably worth the trip for their customers.