German here. Yes, constantly. The only reason to not do it would be taste (personal preference) or sometimes due to pollutants entering the system, which is explicitly communicated by the city.
A kind of “extended” 3-2-1, more a 4-3-2. As nearly everything I host runs on Docker, I usually pause the stack, .tar.bz everything and back that up on several devices (NAS, off-site machine, external HDD).
The neat thing about keeping every database in its own container is the resulting backup “package”, which can easily be restored as a whole without having to mess with db dumps, permissions, etc.