Major energy exporter to Europe and China (and soon other Asian nations)....and growing. If they turn off the spigot, they are going to be on their knees.
Some tech industry and heavy machinery or in support of mining, but most of that is used for military...which leads me to....
A niche military industry that is designed for one primary role. Defense. Yes they have offensive capabilities, and some of that sells...however its more for cross border issues, but nowhere near their defense tech. For example, the S-400 system is highly regarded...and about to be eclipsed by the S-500 system.
The Space Industry has been in decline since the fall of the Soviet Union. But it has made some small strides recently, it appears to be focused more on Russia's need vs. contracting out to other nations. Which makes sense, China, India and a few others are already developing their space industry and don't need to rely so much on Russia, ESA and NASA.
But here is the where the anvil drops on the coyote. Russia's population is less than half of the USA. And only recently started slowly growing after a number of years of shrinking. You can't have a huge economy with numbers like that....add insult to injury, only 70% of that lives in industrialized areas...whereas the rest are deer herders.
https://www.worldometers.info/world-population/population-by-country/