He has done nothing for Russia?
Lets see what the data says:
1) he brought them Miss Universe because Putin asked him to.
2) he did not punish them when his own intelligence agency declared that they had interfered in the 2016 election
3) when Putin annexed Crimea Trump broke U.S. policy and said it was "OK for Russia to keep Crimea"
4) in 2016, Trump blocked language in the Republican platform that would have allowed the U.S. to send lethal weapons to Ukraine, meaning that he prevented Ukraine from being a big risk for invasion
5) Trump was made aware of Russian hacking into our systems but he did not do anything to stop it.
6) Trump gave Russia classified intelligence "free of charge or consequences"
7) Trump never criticized the sham elections in Russia
8) Trump defended Russian invasion of Afghanistan
all of the above were actual actions done that helped Russia. They do not include all the times that Trump praised Putin, making him be more likeable rather than more hateable in the eyes of the world. In addition, there were many times that Trump could have imposed penalties, sanctions, condemnations of Putin and of Russia but didn't