[myrmidon]

This is a good point.

It seems to me that Russia could've easily kept pretending to be a slightly flawed democracy, and it would've been super effective in hoodwinking "the west", but they "blew it" with obvious assassinations even before the Ukraine war.

This raises the question: Why would you ever admit to be totalitarian or a dictator if you have to deal (economically/diplomatically) with softhearted democracies which really hate that?

I think the answer is that just lying about this (to improve your reputation abroad) by itself hurts your local power base. Every signal in that direction undermines that image of strength that dictators rely on to keep in control, and no dictator can stay in power "against" the population because all the instruments to exert that power (prison/murder/army) rely themselves on (parts) of that population.