The fact that 3/4 of the bottles on the shelf is a trifle is true. But not necessarily someone fakes it, only at the beginning a company makes good vodka just to make a good name for itself, and then the taste is different, it starts smoking, the next day some strange conditions in the form of a heavy head, etc.
For example, let's take something from the top shelf - Finland - the clean one a few years ago, after a spontaneously organized party on the second day, I counted 7 one-liter bottles and 3 0.5L during cleanups

- On the second day of the event, maybe we didn't remember everything but nobody was beaten, the police weren't there either, the neighbors didn't complain - so I guess everything is OK

a few days ago my friend had a birthday so I bought myself in an alcohol store called "spirits of the world" - so better in the city - in Finladia with a capacity of 0.7, after opening in the jam the taste was not satisfactory but it was gone anyway.
Now take a cheap "stinker" as an example - you can't live the next day.
And this gastric bitter de luxe - a year ago it was the vodka of the year and somehow no one praised it - on the contrary, recently I had a taste of the mint-flavored vodka, properly chilled, it goes well even without a fillet