I was browsing the internet and I found this https://www.youtube.com/watch?v=1WO0zSStdj8
Apparently, it's a squad of Russian Soldiers refusing to go back to the front line. The fat guy says they were NOT getting food or water (yeah I heard it), I am pretty sure he is right. So, what are the types of conditions you have to face to get water and food at soldiers? I mean, I can understand them not getting ammo and man power to get rid of the dead. Probably manufacturing problems and it's dangerous respectively. But yeah, what else? Why would they not get food and water?
It is really hard. Incredibly hard.
Part of the reason why the USA has such a dominant military is because it has built incredibly long and sturdy supply chains that can move soldiers and materiel around the world quickly to soldiers.
First, you need to get this to the front, which usually requires a supply chain, reserves, and a manufacturing base to replenish reserves. Russia's economy is ok, but this is the first war in a generation and the Russian economy is showing obvious cracks in being able to supply soldiers. You also have Ukraine getting its supplies from the best logistics force in the world and its economic allies.
Second, you need to actually deploy the resources to the front. That usually requires competent military logistics being able to move these supplies. If your logistics people are corrupt or incompetent, that may not happen to the volumes needed.
So, yeah, there appears to be logistics problems with the Russian military.
Seconding this gentlepreferredgenders answer. Logistics is normally easy: don't send soldiers past your logistical reach. The extent of this reach is what determines an armys capacity for offensive maneuvers.
One side of US military is its capacity to project power all around the world, and support that through its logistics apparatus. Few countries can project power in the same way (France and UK, mainly. And to an extent Indonesia).
Russia has its military, including the logistics portion, based around rail transport (For example, the IS10 tank was a good tank for its time, but couldn't be transported very easily like the lighter tanks could, which is one of the factors that lead to USSR shifting her strategy away from heavy tanks). Having a logistics network based on rail makes sense from a defensive perspective, but run into problems when on the offensive - now you have to secure rail infrastructure to expand the logistical network as you go, as well as keep it maintained and not sabotaged. this is resource intensive when dealing with insurgencies.
And even if you get decent control of a decent rail network, then the issue becomes delivering that last mile - in theory easy, but you need logistics hubs that can offload trains and load stuff onto trucks. Even after russia got (some of their) shit together, this was a bottleneck that was struck by himars several times, and videos have shown that even the unexploded logistics hubs are highly inefficient, because for reasons I cannot understand, a lot of the goods aren't stacked on standardized pallets that are easily moved by forklift. Instead you see things such as offloading a truckfull of landmines (probably without their detonators in) the same way you would a pile of gravel; tip the flatbed, and let everything slide off onto the ground, ready to be moved by hand.
Source: i used to be in army logistics. And I like trains.