I can't compare living in the UK to living overseas because I have only lived in the UK, but there are way too many assumptions on this thread. Yes, the UK is overcrowded, and driving is often not a pleasure due to the jam packed roads, but crime, bad schools, daily drudgery - not where I live.
I think age comes into it as well as where you live I am 55 and OH is 62. We had DD late in life and were financially secure by the time she was born. We own our, mortgage free, home. Most of the primary schools in this area are outstanding and two of the nearest high schools are ofsted rated good. Our village is 4 miles from the nearest small market town and a 30 minute drive to two major cities. We live near a railway station and have hourly trains.
DD has had some major health issues that meant we are frequent visitors to the local children's hospital, which is absolutely brilliant - thank goodness for the NHS. I don't know how we would have coped if we had been living somewhere like the US, for example.
I can't compare my lifestyle to that of living abroad, but I am happy with my life here in the UK.
For me, the most depressing thing about living in the UK, apart from the number of cars on the road, is the weather.