[greedo]

Soviet jets and technology wasn't really meant to survive a nuclear war. That would have increased complexity and cost. Everything was really designed more around being disposable.

[gambiting]

I've also heard the argument that steel was in some ways better, because when the enemy is bombing your factories, you can almost always get steel somewhere. Titanium composites, like those used on the Americans planes, not so much.

[atemerev]

...and survive nuclear war. Or at least be capable of doing something useful. Radiation hardening/anti-EMP protection was a great deal.

[PerfectDlite]

And to accomodate lower quality of available technologies and workforce.