Fine by me. But first they can share out all the numerous benefits and investments they've taken more than their share of for far too long. Same for industry and employment.
And once independent can be limited to the same funding as anywhere else. No more extra funding for schools, same spend per head for public transport, same funding for public amenities, culture etc. And with that lower funding they can take their share of any difficulties. Eg no more shipping out low income or benefit claimants. And they'll also need to start taking their share of asylum seekers and all the complex needs and problems they have, not just dumping them minus any extra funding to support them in already struggling areas.
London can be just like everywhere else, rather than the hunger games capitol it's already becoming.
If you mean London should become independent and the rest of the uk continue to subsidise and prioritise it, then no.