Council rates and landlord rents are the first problem.
Then dealing with the Internet rivals who have less overheads and can offer competitive prices.
Add in the drive to make edge of town shopping centres with the large outlet stores over the last 20-30 yrs and it's no surprise to see town centres disappearing.
They're generally littered with charity, gambling, coffee and fast food shops.
Supermarkets morphed from food only shops into one stop mega shops that have everything from food, to clothing to electrical items and even banking.
Then successive governments failed to catch up to a changing world and change the tax laws so companies like Amazon can dodge a lot and make millions whilst crushing competitors.
What exactly do you need from a town centre/high street?
Probably not a great deal if we are all honest.
Having to deal with shop staff who can't be arsed, or idiots wandering around blocking the aisles with their trollies /pushchairs etc whilst chatting to their mates or failing to control their horde of children isn't really that appealing to someone when they can buy online and get same or next day.
Then you've got thieves trying to pick your pocket, especially in the bigger cities.
Even retail parks present the problem of people who're simply incapable of parking within the lines...
Covid showed how selfish/stupid people can be when out shopping as they're incapable of following really simple guidelines/one way systems in shops

It also helped speed up the process of taking people into the world of online shopping instead.
Books - Kindle, takes up less space, wider variety, better prices and some authors do their first book for free, especially if its the start of a series.
Music - YouTube, Amazon, Spotify etc negates the need for physical CD's, records etc unless you're a purist.
Personally I pay £7.99 a month for youtube so I can stream directly to one of my cars and I can listen to lots of remixes done my some really talented people who aren't, or can't, be mainstream.
Films/TV - again why collect films on DvD etc when pretty much everything can be watched or purchased on line?
No need to have a physical collection that needs to be updated with the latest format.
Clothes - there are online stores that offer free returns, saves the need to go into a shop and try things on, but the majority of people have a favoured clothes shop so they already know which size is correct for that particular shop so they can order online from there.
Food - grocery can be delivered, same with take out food and other stuff like fags/booze.
Gaming - the likes of Steam, Xbox and Sony regularly offer great deals online, inc the ability to oay x amount a month to play a wide range of games without actually committing yourself to buying them, making physical shops redundant.
I don't need many actual normal shops, simply because they offer me very little, same for millions of other people and many of them aren't open at accessible times during the week so people finish work and the only places they can usually shop are online or at a retail park.
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