I’ve done a smidge over 200mph in Germany on zee autobahn. For me the last 40mph, the 160-200 feels proper fast and you sense if something goes wrong it’ll be huge. The issue with big speeds is less about driving skill and more about observation. The biggest risks at such speeds are 120mph brick walls that just happen to be travelling at 80mph. One of those pulls out and it’s boom. I’ve found the autobahn tends to illicit better driving standards. Those don’t exist in Britain in most places.
Is the act of driving at 120mph dangerous in itself, not really. You can what if to make it dangerous, but in a fast car it really is easy and effortless. The danger comes mainly from others who won’t be expecting it but the onus is on the person doing it not those around them, outside of Germany of course.
I can’t condone big speeds on busy British roads.