Here in the US, the NEC specifies a one-foot separation for low voltage unless crossing at a perpendicular angle. Low voltage is generally a specialty, so a lot of electricians don’t know.

The bigger issue is that there are tons of electricians that never went through apprenticeships and who never picked up and read a copy of the code (which has major changes every three years). The result is a lot of cargo cult installation which may or may not actually be correct.