It might not be a popular thought here, but I believe this might be the extent of the Russian army, Air Force, and navy capabilities.

I think it's more the Russian government realizing that, in order to prosecute this war as it probably should be prosecuted, they would need to take the irrecovable final step: de facto abandonment of the post-1991 political order and re-Sovietization of the Russian economy. This, we know, is something that they're extremely reluctant to do. Over the past twenty years, they've made certain steps in this direction, but only when absolutely compelled by circumstances, and when the alternative is literal destruction of Russia. Some of this reluctance stems from liberal ideology, which still has a very strong hold in most countries; some of it is probably from a mass of mid-level bureaucrats and people in the security services (Putin's original base of support) who are genuinely patriotic, but also shell-shocked from the 90s, and who thus have an irrational but completely understandable fear of anything which will, in the common phrase, "rock the boat." But it all adds up to a government which feels that the status quo is extremely fragile, and hence values stability above almost anything else; which is to say that they are "conservative" in the only real meaning of the term.

Either Shoigu or Lavrov is supposed to have said last year that when this conflict ends, "we will have the Soviet Union back." There's a truth to that, because Russia right now is like a bullied person, or a battered woman, under the boot of that thug which is the collective west; the person under the boot has been able to dictate more and more terms of late, but ultimate emancipation still means throwing off the bully, climbing to one's feet, and socking him hard in the jaw. When that step is taken, the bullied person becomes finally himself again, and Russia again becomes the USSR, by force of material reality and the natural progression of the real modes of production; but it is a risky step, and the politicians in Moscow will not take it unless forced.