Different economics apply to tourist towns and cities as their centres have many more wealthier visitors spending money.
My nearest town has suffered a great deal with the loss of well known stores, leaving empty stores to to be filled by charity shops who often pay little or no rent or rates, no wages and nothing for their stock. Hardly surprising that small independents are being priced out of the market.
Internet shopping is here to stay, so the only way to revitalise town centres is to make them attractive easy to reach destinations of choice for services. Eventually the NHS will create mega doctors practices and health centres in town centres, but the will need to be well served by public transport links for those without own transport . With a bit of joined up thinking they will join the dentists, opticians, chiropodists, cafes, bars restaurants, gyms, fitness centres, hairdressers, tattoo parlours and nail bars and cinema and theatres and live entertainment, and anything else you can't buy online. Eventually retailers will open smaller browsing stores where you can go to see the choice of products IRL, to try them out, see the colours, quality, sizes on offer and try things on for size and fit, but your final selection will be dispatched to your home from a warehouse, so you don't have to carry it home on public transport and so the store isn't paying to store stock in prime retail areas.
It's interesting to see Amazon opening physical stores now that they have shut down the competition and whether they are working..
I think it will take 20-30 years for all this to happen in many towns unless there is some serious joined up thinking.