I've lived in London for 21 years and I'm now in my fifth year of studying in West Yorkshire. So I like to think I've experienced a bit of both worlds but in all honesty, London is my home and it always will be. I'm not saying that as a born-and-bred southerner but because I believe it is literally the best place in the UK and I can't imagine living anywhere else. London is full of arts, culture, entertainment and has some of the best shopping areas you will find in the UK. Not to mention that it's full of history and is home to centres at the forefront of Medicine, Engineering, technology, politics and business. Yes, you might argue that it is expensive and has some really dangerous areas (which I agree with) but growing up in London is an exciting and unforgettable experience that will stay with me for the rest of my life. Who needs the Peak District or the Yorkshire Dales when you have Regent's Park, Hyde Park and Green Park within walking distance of the most lively areas of London? The suburbs are also full of green spaces and I've spent many summer afternoons enjoying myself in those, so I don't think that's a reason to turn your nose up at London. I like to think that my life is so much better today because I grew up in London, and I hate to imagine what life would have been like if I'd lived anywhere north of the Midlands.
I'm doing my best to get a place to study in London next year so I can return home - that's how much I love the city.
While I did enjoy my first 2-3 years in West Yorkshire, nowadays everything has become extremely boring and repetitive. Everything (and I mean EVERY single event) I come across at university involves alcohol, and that is incredibly isolating for someone who doesn't drink. The only things I can spend my days doing here in Leeds are working in the library or watching films, which gets very boring. I can walk around all of Leeds city centre in 1 hour, but in London there is so much to explore and even after living there all my life, there are still areas I have never been to. It's a city that's always on the move and constantly changing with new infrastructure, entrepreneurial opportunities and even fame and fortune. On the other hand, northern cities have stagnated because there is no investment in local economy. Unemployment is high and (I'm sure) the proportion of people on benefits is much higher up north than in London. Lots of professions nowadays offer very few jobs outside London because the city is just so glamorous and irresistible. Obviously the housing crisis is a huge issue but that's only because there is next to nothing appealing about most other cities, except for some like Birmingham, Manchester or Leicester. The only reason I would consider moving to another city is if I can't afford a house in London, but as I already live there and my family are (I hope) never selling the house, I'm happy.
At least if I was in London, I wouldn't have to worry about being pressurised into drinking alcohol because the Asian communities are large enough to get involved with. Maybe it's because all my closest friends are in London but the fact is that I see them (on the occasional weekend trip home) more than I see my friends at uni because people here are so two-faced and stuck-up. In a massive student city like Leeds, alcohol means more to people than anything else whereas London is large enough for me to find non-alcohol events and religious gatherings which just don't exist here. London is truly multicultural because there are massive events happening to cater to every community and something different happening every day of the week, whereas Leeds is only multicultural because there's a bit of diversity in the people living here. When you have a population that's roughly 10% South Asian but NOTHING specific for South Asian people to enjoy, you end up making your own entertainment at home and becoming very distant from people because it's hard to cement friendships unless you drink alcohol. That never happens to me in London because there's so much else going on that I hardly care whether people are drinking or not. It's so easy to meet people from different backgrounds in London compared to being stuck in this rubbish student bubble in Leeds.
While the northern cities have their benefits (like being a lot cheaper and having more value for money), IMO those are far outweighed by the excitement of living in London and having the world on your doorstep. In London I would go through rain, snow and sleet to enjoy places like Borough Market, Green Street, Edgware Road, Southall Broadway, Shepherd's Bush, Oxford Street, Regent Street, Piccadilly Circus, Shaftesbury Avenue, Wembley, Neasden, Finchley, Stratford and Ilford - whereas in Leeds there is just no point going out even if it's a nice day. What is there to enjoy apart from a city centre full of generic shops and some big parks? In London I have the chance to chase some very lucrative opportunities that I just wouldn't find up north.
TBH I don't think you can form an impression of a city just by going past it on the train, but in this case you're not far off, OP. There's no ambition or passion in these northern cities, and the only reason I'm here is because I couldn't get a place at university in London. I'll be moving back home as soon as I'm done here because I'm fed up of Leeds. I reckon the only decent place to live in the north is Manchester - everywhere else is just dismal.