I have lived in the same town since the 1970s, but have really noticed a change in the last five or six years.
Basically, I live in a medium-sized market town about 60 miles out of London. Since the early 2000s, the population has massively increased. In other words, it's now a market town with the population of a small city. The town itself is ringed by horrible new housing estates with hundreds of awful rabbit hutch 'new builds' jammed together. The roads have become utterly hellish as well, and all you hear morning and night are modified engines screeching up and down. Basically, there are too many people squeezed into what used to be a sleepy market town.
But it's also the people themselves. Apparently, there is some kind of deal/policy to move 'problem families' out of London and onto a couple of these new estates. I went into town today and felt really uncomfortable. In the middle of the high street, a BMW had parked, engine running, on a double yellow line. Drill music was blaring out and four young guys were sitting in it, obviously waiting for someone. As I passed, the driver leaned out and said "what da fuck you lookin at?" It really shook me. This was the middle of the day! Everywhere I went there seemed to be groups of young guys wandering about, trousers half way down their legs. There have also been several stabbings recently (none fatal, thankfully, but I guess it's only a matter of time). It used to be a relatively quiet, relatively pleasant town. I now hate the place. That's the last time I'll be going in for a while, that's for sure.