I was born and raised in London and am lucky to live in a lovely quiet corner of zone 1. I often fantasise about living by the sea or in the countryside, but every time I go on holiday to a more remote part of the country or to a smaller city, I'm reminded of all the reasons why I'll always be a Londoner, and I love coming home.
I love the variety and diversity, and the incredible culture, arts, food, etc. I love the architecture, the history, and the huge amount of green space. I love that I am still always discovering new things after 30+ years of living here, and that the city is constantly changing and evolving while also staying reassuringly the same in all the ways that matter.
Outside of London, everything seems to stop at 5pm. Very little money has been put into maintaining arts and culture in the regions, with many towns not even having so much as a cinema, let alone galleries or theatres. Public transport outside of London and the south east is dire, which means you're reliant on cars.
I couldn't cope living in a small town or city where I feel like I would have done everything there is to do several times over after a couple of months of living there. I'd also struggle not having a diverse group of people to befriend - I love the fact that I've got friends from all over the world here in London, and you just don't get that cultural mix in much of the UK.
I'm used to the hustle and bustle and noise and pollution and I don't notice it, but I do notice the quietness and lack of life when I'm away. Sometimes I crave that and I love being able to walk for miles without seeing another soul when I go to the South West or Yorkshire on holiday, but I couldn't have that isolation as my life.
So no, OP, you're not being unreasonable. I do think nowhere else compares to London - in my view it's the best city in the world. Even after all this time I still get a little thrill when I walk across Waterloo Bridge at night and see the city lights sparkling in the river. Nothing beats that view for me!