The Russians have plenty of gold, they should just pay-up with that.

Why should they do that ??
Not trying to be argumentative but asking a question.
The West especially the USA is engaged in economic war with Russia, removing them from Swift, sanctioning their Central Bank, and banning their oil.
Most of the debt Russia has is owned by the West, what better way to say FU to the West by Russia and default on their debts.
The next question is what would Russia do then ?? China is a fountain of money and wants to screw the West as much as Russia.
If I were Russia I would refuse to pay the debts and default and see what happens to Western Banks and other investment companies who have issued large amounts of Credit Default Swaps that could cause the crisis of 2008 to be considered a skirmish.
“The Russians have plenty of gold, they should just pay-up with that.”
They also have $600B in hard currency. But why bother, at this point?