When it comes down to it, people would rather sit at home on the sofa and order stuff on Amazon than go and shop in the high street. It's all very well moaning but if you don't use it, you lose it. It's all about supply and demand.
We only visit 2 cities, nailedit, to attend hospitals! I can vouch from the car parking situation that both are like adults' Fisher-Price Activity Centres at full capacity. No help to your question at all, sorry :)
No city, but, towns full of empty shops. Charity shops, cafes, and expensive parking. Plus extortionate business rates have all but destroyed any enterprise.
The street I'm most disappointed with is Oxford Street in central London.
Most of the top name stores have gone. There are plenty of tourist shops selling their tat! Very different to when I worked in the area.
Very small town population 8500. Now full of Estate Agents, cafes, bistros, hairdressers and two factory shops charity shops. Never go into the town centre now except to one pub/restaurant. In fact I wouldn't call it a Town centre now. Only shop online now and out of town Morrisons and lidls.
I live 10 miles from a city centre and I havent visited for a couple of years. I used to go in every day to work but dont need to anymore. Instead I shop either online or in the local small towns and find it far less congested, more affordable and more enjoyable.
However even those smaller towns are very quiet but I think thats the January effect. No money around after Christmas and cold weather.