Some graffiti is, I think, traditional at this point and a good mural can do wonders to humanize it. I have a feeling that patterns are not actually going to improve it though. The problem is often the form rather than what the material looks like. You could paint it to look like a row of thatched cottages but that would to me be even more depressing.
You are also then committed to repainting it regularly or it's going to quickly look even worse than when you started.
Vines in my opinion are great dicore maybe that's because I'm a sucker for abandoned building vibes idk what it is that makes me love looking at abandoned buildings it's one of the reasons I love portal 2's abandoned sci Fi look if I wasn't for the high heights and turrets I would love to explore abandoned apeture
Graffiti is vandalism. It is not traditional, and it's not art. It's a crime; there is no exception unless it's done on private property with permission from the property owner.