Russia's military budget in size is sufficient for anything Russia would need defense-wise (and even aggression-wise, TBF) to a full extent. It's just that most of the money was being stolen through all these years. It's rotten to the bone.

About glory days - USSR's military was really something "second best" somewhere in the 50s, when it was a system built for some actual overarching doctrine.

With every year passing Soviet bureaucracy was more and more entangling itself into a knot of financing and prestige and cabinet power struggles, so by 80s it would have like 4-8 simultaneously produced and operated models of tanks, with similar technology and details etc, but similar wouldn't mean interchangeable, in fact there would be almost no interchangeable details between them. It was similar in any other area. Standardization (which Commies love to present as planned economy's advantage) was a farce.

The bureaucratic system responsible for every part of the system would fight tooth and nail for some external benefits and provide some external service, soldiers and students would be used on harvest campaigns and housing construction, and the main purpose would be cemented, never reevaluated (I mean, everything changes in 5 years in real world in any area, and the Soviet doctrine has not evolved much between Korea and Afghanistan), and in fact lost.

Which is why, say, Soviet personnel carriers wouldn't protect against anything. Their purpose was to move fast, be amphibious, be hermetic, be cheap to produce. Cause the plan was that after all the boom-boom stops in the Global Thermonuclear War, one would need to move infantry over burnt irradiated land, fast.

It really was in planning and function a bit like the Galactic Empire, be it the Azimov's one or the Star Wars one.