I have no experience with Soviet electrical standards but as a brainwashed American I would assume this is a bit out of an outlier, because the Euro standard is

I have no experience with Soviet electrical standards but as a brainwashed American I would assume this is a bit out of an outlier, because the Euro standard is objectively better and the Soviet one is so obviously bad/flawed/worse/whatever, that you don't really have two competing standards; you have the good one that is 100% of new installs/refurbs, and the bad one that only ever gets ripped out. This is in contrast to e.g. databases where most of them are "good enough" and the decision to use one over the other is much more subjective.