I agree with you to some extent. A year ago, I wanted to become a lawyer in the city, until I met city lawyers. A lot of them work 16 hour days, every day. They basically sit behind a desk and do paperwork. None of the work is actually of interest or exciting. It's completely dull. I think there is more to life than having a career and so would not find this fulfilling. Plus, the majority of city lawyers I met (and I'm back up by at least one study) are narcissistic, selfish and borderline sociopathic and obsessed with money. They believe they are better than people who earn less money. Personally, I cannot tolerate people with this attitude. I would blow after a day working with them.
But, there are other city jobs out there that doesn't include sitting behind the desk. London is a huge historical place. If you're interested in history then you could certainly have an active career. It's a huge tourist hub, so if you specialise in travel and tourism, you could do something with that. Some of the worlds most successful clothing designers are based in London. Fashion is a very creative, active career. Talking about being creative, London is huge for the art trade, art museums and artists. That definitely does not mean sitting in a office all day checking emails and accounts.