Just next street, 6 years ago, some guys painted a Zebrastreifen, and got charged for Serious interference with road traffic: https://www.dnn.de/lokales/dresden/falscher-zebrastreifen-in...
(do note that "serious" or "schwer" (lit. heavy) is a qualifier in german law, that increases the charges significantly. The serious part here is that it isn't some alteration that can be immediately removed (e.g. a traffic cone))
Update on that other situation in the district of Neustadt that you mentioned: The city actually just completed a legal crosswalk there, just last week. Here's the article by our public broadcast: https://www.mdr.de/nachrichten/sachsen/dresden/dresden-radeb...
Indeed, it could lead to cars slowing down and who could want that in Autoland germany.
[1] https://medium.com/asecuritysite-when-bob-met-alice/traffic-...
And another in Dresden: https://www.youtube.com/watch?v=cQUpQZAeA3w https://www.diesachsen.de/en/politics/a-zebra-crossing-in-dr... "In the summer of 2025, unknown individuals painted a crosswalk on the roadway along the busy street in Neustadt to provide safe access to the Heinrich Schütz Conservatory. The city promptly blocked off the crossing with warning cones [...] stating that unauthorized crosswalks constitute not only property damage but also a dangerous interference with traffic. Furthermore, traffic signs installed without authorization constitute an administrative offense under the Road Traffic Code."
And an example in Saskatoon, visible only in the 2015 street view image https://maps.app.goo.gl/3zWAkjtSEATswcWm8