Buran is much less of a copy than it looks like. It's superficially similar as it has the same mission profile, which was basically because Soviet officials wanted to be able to keep up with whatever nefarious things the Americans might be doing in orbit with such a thing, even if they weren't sure what that would be. But it's far from being a copy in terms of technology, materials, construction, or even major things like the booster.
Agreed. If anything, the technologically interesting parts compare better to the titanium submarine example, as the RD-170 engine that powered the Energia rocket that lifted the Buran was at least in some ways more sophisticated than anything Americans had at the time, and in particular, used an oxygen-rich staged combustion fuel cycle that American engineers had considered but dismissed as being impossible. Aerojet engineers didn't actually believe the Russians had even built such an engine until they were able to examine one in person after the end of the Cold War.
You can read the parent article for more details. https://en.m.wikipedia.org/wiki/Buran_programme
A much better counterpoint would have been the Tu-4, which was in every detail a reverse-engineered B-29: https://en.wikipedia.org/wiki/Tupolev_Tu-4