Ewan .... aside from thinking good Street-Art can be great, especially where it transforms a derelict and unloved urban corner, I'm with you on that .... when you look at the old photographs and see how good our towns looked clean and uncluttered 100 years ago you don't feel they've been improved.
One thing I noticed moving to the NE 30+ years ago (and it took me quite a while to work out what I wasn't seeing) was that the towns looked much neater than down south ..... then I twigged that the winds meant that BT, Hydro etc put all their cables underground ... makes a huge difference.
K