What was left of the Soviet-era mobilization system was dismantled by Minister of Defense Serdyukov over a decade ago. Russia does not have the facilities nor the personnel to bring a large number of reservists up to speed and to equip them very quickly. Much of the modern equipment that has been adequately maintained is already destroyed. Sanctions are not helping when it comes to manufacturing new equipment or repairing existing equipment. To a large degree, Russian artillery pieces are worn out and in need of an overhaul. The barrels are only good for so many rounds fired. Similarly, Soviet tank engines are kaputt only after about 1000 hours of use.

If Russia's goal is to shore up the personnel shortage in the coming weeks, it may be able to put more bodies to the front to help man the many understrength BTGs but the combat value of the newly conscripted men will be questionable.

Russia's supply system is struggling to adequately supply the existing manpower. Greatly expanding the manpower at the front would further complicate things.

If Ukraine continues to receive adequate supplies and maintenance from its partners, it should be able to inflict a lot of casualties and destroy a lot of equipment in the process.

The modern world is much less forgiving of the kind of abysmal leadership and lack of professionalism found in militaries like Russia's than in past centuries. This is due to the firepower, precision and accuracy of modern weapon systems. Russia no longer even has the numbers to make up for all of its flaws with senseless human wave attacks.

Not even tactical nukes would solve any of Russia's problems.

At the end of the day, the main problem will be whether Vladolf Putler is mad enough to use strategic nukes when he realizes he's facing an ignominious defeat and ouster/death and whether the chain of command will have a modern equivalent of Admiral Arhipov or a few to say fuck it and put the olm out of his misery should it come to that.