Rebuild something similar to the Soviet Union, push NATO back from eastern Europe, make Russia population become sustainable.
He achieved a few of these things. Russia has expanded during his rule, he re-conquered Chechnya, parts of Georgia and Crimea. He was able to avoid a NATO takeover in Ukraine. Russian fertility is below replacement but is much higher than in the 90s.
He has been unable to put the Russian economy into a strong position, they have the resources and the technology but they simply can't get their shit together to produce consumer goods. Compare it with China, China is in many ways behind Russia in technology, they still rely on them for a lot of more advanced stuff like jet engines but they are able to produce a lot of stuff to make foreign currency.