Any kind of private person or company cannot install cameras looking into public spaces at all (and yes, that includes Ring doorbells that can see the street or even just part of the sidewalk). While many of those illegal uses might fly under the radar the general ban of those uses also means that they are relatively rare and not something just anyone would do.
Public institutions can install cameras seeing public spaces but they are limited by law (there needs to be a valid obvious reason for the camera to be there and the use needs to be proportionate), so blanket complete coverage of public spaces is just not happening (yeah, public institutions can probably find a bullshit excuse for any place but the culture these laws create mean that cameras are just used a lot less). Cameras in general are where you would expect them to be (e.g. around high profile government buildings), not in some random street somewhere.
Actually, the most recent episode of "Aktenzeichen XY ... ungelöst"[0] (a German TV show that is basically the same as "Crimewatch" or "America's Most Wanted", but predating both of them) mentioned such a case [1].
Some guy in Berlin sent bombs via mail back in 2017/2018 and demanded a ransom paid in Bitcoin. They didn't explain the details, but apparently police did trace a transaction to that wallet back to some Bitcoin vending machine and got a nice picture from there.
[0] https://en.wikipedia.org/wiki/Aktenzeichen_XY_…_ungelöst
[1] https://wikixy.de/Sendung_vom_12.05.2021#Die_Studiof.C3.A4ll...
On the other hand, if he did the cash drops with Bitcoin instead, it would be much harder to catch him -- but there wouldn't be any Gyro Gearloose devices, so we'd never heard about it either.