According to some sources, the Russian railroad system - which in many areas is the sole means of transporting people and goods, and across the board is of strategic importance - is being crippled by the sanctions imposed on the country. The shortage of ball bearings apparently took tens of thousands of railroad cars out of circulation. That represents 20-30% of all railroad cars present. Repair facilities can not operate properly due to a shortage of various replacement parts and service materials.
This represents a major issue affecting all aspects of life in Russia but especially the military which relies heavily on the railroad for transporting personnel, equipment, etc. It also highlights the fundamental weakness of an economy based on trade in gifts of nature (oil, gas, timber, etc.) When that is your economy, you should be very careful projecting military might - the people you threaten might just choose to no longer provide you the parts you need to operate and then your might might turn out not to be so, well, mighty.
References
SITREP: Russian Rail Sidelined By Sanctions
Sean Spoons, SOFREP, 4 September 2022