None of these articles seem to mention WHY the tanks are designed this way (although I admit I just searched for keywords).
As far as I know, it is because the current gen of Russian tanks were designed for how they envisioned WW3 40 years ago [1]. Basically the tanks would follow nuclear strikes, and making humans load the ammunition would make them die a lot quicker from radiation, so they made an autoloader.
[1] https://en.wikipedia.org/wiki/Seven_Days_to_the_River_Rhine