Interesting thread as I have hyst been fretting about the anount of people we onow locally who seem to all be up and moving elsewhere!
We're SE London and living in a decent area in a large house, that needs masses of work but is a 'forever home'.
In the last 2 weeks 3 families I know have either gone ir have their homes on the market. I'm feeling a bit discombobulated as part of what I love about living here is how close we live to other families with children that are at school and friends with ours. It all of a sudden feels like a mass exodus, and I'm feeling a bit bereft.. silly I know.
For context I am born and bred in London, albeit a different area to where we are now, but have been in our current area for over 20 years so very familiar with it/ love the community etc, and can be in C. London in about 20 mins by train, or Brixton is 10 mins on the bus for the tube.
I had a great time as a teen/ young adult.. was out loads at gigs/ pubs etc and never needed to rely on my dad as a taxi service. I kind of think I want my kids to enjoy the same freedom, but we have no close family near us, my mum is still in our original part of London, but is old and frail and my dad has gone now. OH's parents are younger and have been part of our DC's lives a lot more, but they live about 150 miles away so we haven't seem them for a long time.
Not sure what I'm trying to say here, but just I can understand OP'S questioning as I wonder if our kids would be happier living in the countryside/ nearer to GP's etc.
Having said all that, love our project house, big garden, nice neighbours and the primary my kids go to is great. Secondaries around here are good-ish depending on where you go, so staying put seems the way to go.
I guess if you leave London and then regret it, moving back is quite difficult financially..