It's not a trade route but import route for Russia. More than half of Russia's exports to PRC is oil, gas, coal and metal ores which are mostly transported through the land routes. And remember that while Russia's biggest trade partner is already China and from Chinese perspective it's as big as Australia for example Russia is in the group of 'important but not essential' economic partners. Treating PRC as the single vector(that you and many here are fans of) can have it's positives if done properly (like making the people in Russia better over time, and it depends on the other side's intentions) but has gigantic tradeoffs like economic and political vassalisation over time. China opened this week a rail line connecting it with Europe bypassing Russia entirely for example.
I think that you don't understand why ships always win compared to rail. It consists of three simple words: volume, time and money. Those factors makes your predictions useless unless you can make another revolution in trade on this planet.