To Pippi
Welcome to the Forum and the area!
I could be smug and say that all those living in the "grand and impressive houses" don't make much use of the pavements as they use their cars all the time.

Why not take some photos of those "diabolical" pavements and send them to "Love Lewisham" (when the Council's website is working again after the weekend, as it is closed for maintenance at present). Have you asked your local councillors to come and take a walk with you? Duncombe and Lowther Hills have some steep bits, along with big old trees whose roots tend to make a mess of pavements. But if you're feeling really fit, try Brockley Park!

You will find that repairs get done quite fast once the problems have been registered been registered: give it a try.