The Russian economy is deeply flawed structurally. The biggest firms are state funded and have a monopoly. Entrepreneurship is minimal in Russia. Their tender processes are similar to our 2G scam, but no one bothers.
Even with all their scientific expertise, they have a minimal presence in the consumer goods industry. Their flawed system prevents their technical knowledge from turning into economic gain, as there will never be a Russian Volkswagen, or Microsoft, or even Tata for that matter. This is the reason why, as you mentioned, they're placing their bets on tying up with China. (We know how that'll work out).
They also have a huge divestment problem, where the rich take their wealth and invest it in the west, as there is hardly anything to invest in in Russia except oil. Their pensions and salaries are also falling hard.
Overall the Russian economy is still fundamentally reliant on oil and gas. At this point, they're a Saudi Arabia who can make fighter planes. Contrast this with a country like Poland, which has modernized its economy and has already overtaken Russia in terms of per capita income and standard of living. Let us not even begin comparing the Russian economy to that of Germany.