Supposedly, equipment made by the USSR was designed to fight a short war, and is not necessarily designed to be durable or fixable. This gave some advantages in cost, weight, performance, etc.
Equipment made by the Russians during the era of communism was a lot of garbage produced by enslaved, despairing peoples who knew they lived in a rotten, corrupted society and a brutal police state. “The state pretends to pay us so we pretend to work’’ the saying went. In addition millions of those workers were chronic drunks. For a good read on this read Viktor Blenko’s “MiG Pilot’’.