The size of economy in my view matters a great deal since that defines your natural market as well as your "safe" market. The size of available resource is obviously dependent on the size of the economy. Less visible perhaps is with production or manufacturing and for when one has to import/export to survive, the risk of development just increased significantly. Risk of course is a big impediment to development, so size matters.
Given the strength of the Soviet military, one often forget how a small GDP they had. Soviet era numbers are hard to come by now, but looking at projected number for this year (2018):
GDP (trillion dollars/1,000,000 million dollars)
1 @ 20.2 USA
2 @ 13.1 China
3 @ 5.1 Japan
4 @ 3.9 Germany
5 @ 2.8 France
... UK, India, Brazil, Italy, Canada
11@ 1.60 Korea (presumably South Korea only)
12@ 1.52 Russia
13@ 1.48 Australia
14@ 1.42 Spain
In GDP terms, Russia is not even the size of South Korea. It is less than 10% of the USA and just over 10% of China.
The other telling stat PPP:
1 @ 25.1 China
2 @ 20.2 USA
3 @ 10.3 India
4 @ 5.55 Japan
5 @ 4.31 Germany,
6 @ 4.14 Russia
Given Russia's limited size in terms of GDP/PPP, they just don't have the scale of what the larger economies can support. Technology development in almost all known era and country came from first use and learn from others, then copy/imitate, then create their own almost as good, then, perhaps exceed that of the original tech leader. But to "create your own" you need a market for it and their market simply is not that big.
In my view, given their small size economy, Russia is doing exceedingly well.However, I think Russia needs to buy from itself more - that will keep more of the dollars in-country for further development. What to me is clear is: Russia is too small to compete with China or USA on it's own, it needs partners.
EU seems to be suffering from self-inflicted wounds in their economy. They just absorbed millions of adults to educate. While it is too new to be reflected in current number yet, but absorbing millions of uneducated adults has to take a toll. This is not an era of human muscle powered economy so cheap labor is not going to help technology much. Until those new arrivals risen to par, EU is in "holding up" or "catch-up back to what it was" mode. Besides, there is the risk of needing another generation or more for that to happen.
If one takes EU (as partners to Russia) out of the picture, there is Japan, India, and Korea in their near-by geography. That will put them near as "viable competitor" to the big-two but still not as big. Lacking a bigger safe-market or a bigger resource pool, Russian technology development (in manufacturing or creating new technology) will have a hard time keeping up with the big-two. The future will be an interesting one.
Edit - opps, forgot to include the link to the GDP/PPP source I used:
http://statisticstimes.com/economy/countries-by-projected-gdp.php