We are born and bred Londoners but will be moving out next year. Our main drivers for moving are the typical ones of schools and wanting more space, but increasingly I am beginning to feel somewhat 'over' London. I think it's probably different if you're in one of the chichi,trendy areas, or the buzzy cultural centre, but accessing all that from our Zone 5 suburb now just feels like a massive effort (especially since the trains have been shit since the pandemic as the normal pre-pandemic service was never restored). It's actually now quicker to get in from the areas of Herts/Essex we've been looking at.
Our area also happens to take the honour of the most mortgaged place in the U.K. and it really shows - the people here seem frazzled and 'hard', there's little real sense of community, and I think the stresses of keeping everything going are increasingly manifesting in rude and selfish behaviour. Our area, like many, has already gone significantly downhill since (take your pick) austerity/Brexit/covid/the COL crisis...
While there are undoubtedly more opportunities for young people in London, we also feel that DD will have more freedom as a teen if we move (we're looking at a large market town, not a village). Friends with teens here don't really allow them much independence due to heavy traffic and increasing crime levels, and local schools operate community patrols and tell the kids to go straight home to avoid being targeted for muggings etc. When we recently visited the town we're looking lots of the secondary kids were hanging out in the town centre cafes with friends and it felt like quite a nice contrast.
I'd caveat this by saying that, as several pps have said, the specific area you're looking to move to is crucial. Since our families are still based in London we've decided to do the 'halfway house' thing of moving to Hertfordshire, so we can easily get back to visit and DD will still be within commuting distance should she want a London university or end up working there.
She's also currently only in Year 2, and we're planning the move earlier than we really need to to give her (and us) time to build new school friendships before she has to move on again for secondary. I think it gets harder after about Year 4 (I've taught a few new arrivals who never really settled in years 5 and 6) but still doable as long as it's before secondary.