I'm curious too. Are they proud that people spent time removing the art? Are they sad it gets removed? Want to show how bad they do their job? Or is that just another kind of art?

this is it, i feel it's just a different kind of art. if you look closely every one has a different method to cover graffiti and they are actually making art even if they don't know it. they have their own flair, taste. they don't do a perfect job so it's like a different kind of graffiti in itself

This is art

The author of the website is linked to a book called "The death of graffiti" (available online, in German [1]), a collection of essays on graffiti (its perception, culture, history, commercialization, etc).

I guess this website was intended as a companion art piece for the book, but which one came first I couldn't say.

[1] https://menetekel.org/