By 'the high street', do you mean Bristol Road (closest actual shopping street to canpus, the one with the Aldi and the Korean supermarket)? Or one of the main streets in the city centre?
Both DS1 and DD went to Birmingham and DS1 moved back there after doing a Master's in Bristol. Granted, he currently lives on a lovely leafy road in Edgbaston, but both he and DD were in 'Selly Oak Village' halls in first year (Jarratt and the then brand new Battery Park, respectively) and between them have lived in six different roads in the badlands of B29 that is the main habitat of the UoB student. Tbh, one of my main concerns for DD in her second year house was that it shared a garden space with the house next door and I was worried that in the height of the covid 'tier four' nonsense, some busybody would see them out there at the same time and report them for household mixing.
DS1 did once comment that one of the downsides of staying 'up' during the summer (he lived actually on Bristol Road at the time) was that he had sometimes been approached by dealers, presumably feeling the pinch with many of their regular customers having gone back home. It wasn't something that had happened during term time, and if it ever happened to DD, it obviously didn't bother her enough to mention it.
Where we live, in the second most desirable bit of our own bot enormous city, over a relatively short period of time a few years back we had a young person murdered by someone local and known to him, an older man murdered by someone local but a total stranger to him - and our longstanding MP murdered whilst going about his constituency business. At least that wasn't carried out by a local.. These things can and do happen anywhere.
Yes, parts of Birmingham are probably a bit 'rougher' than a lot of students are used to, but it is a city. And the homeless and 'druggies' are everywhere (lovely, of course, if you live somewhere where neither ever make themselves known, but I'd really be quite surprised if neither group isn't around somewhere).