I've had similar sentiments, especially after enjoying life outside of the UK. Admittedly, part of that was supported by a London salary, although I could have lived on far less. The quality of life here, compared to other (even less well off) places is shockingly poor for how expensive it is, unless you're wealthy enough to avoid most of the problems (including the tax burden).

I'm fine with staying in the UK in the short term but I have huge misgivings about starting a family and raising kids here. If I were to do so, they'd be enjoying the things that most people here don't have the luxury of (private education, etc.).