"Maybe the high street really is dead nowadays."
The pressure now is to convert high street shops into housing. In recent years I have seen several local business sites razed and replaced by apartment blocks several storeys high.
The old established family businesses' shops are generally sandwiched in an ancient terrace row - so they have been converted to pubs, chain restaurants, and takeaways.
No doubt their customers are the London commuters who have taken the new apartments. They moved because they couldn't afford to live in London any more. The locals can't afford to buy/rent the new apartments - so are being pushed out to more distant areas - and then commuting back for work.