In the big picture it's fun to see countries always making the same mistakes in preparing for wars.
They plan them to be swift, and avoid raising taxes and other income for the war effort, while not recruiting or producing arms in large numbers.
Germany in WWII planned a swift war and their "war machine" didn't peak until 1944.
The US has been in several wars planned to be much shorter and cheaper than they were, Korea, Vietnam, Iraq, Afghanistan...
(The US never raised taxes for war effort in those wars, but simply increased debt).
Financially the attacking party always bears the heaviest burden, with longer supply lines and larger numbers in hostile territory with no local support. Raiding replaces supplies and salaries, tanking efforts to win over the local population. Russia is trying to show how their occupied areas are better off in the Russian Federation, with peace and political stability. Putin recently spoke of "... Ukraine as a "brotherly nation"*. But the reality is hard to fake, and the extensive war crimes are undermining that effort.
The question now is who time is working for? Typically time is against the aggressor. If Russia doesn't win, they lose, and if Ukraine doesn't lose, they win. If the aggressor loses momentum it's hard to build up again, but that is probably what's happening with Russia's "build-up", and only a large scale campaign can bring that.
Russia is presumably in this for the long haul. Putin knows he has superior numbers, and with continued mobilisation and construction of war material they will seriously threaten Ukraine in 1, 2, 3 years. I doubt the current Russian/Belarus forces will be the final blow.
The unknown factor is how much the West will continue to support Ukraine, and with what.
President Vladimir Putin says he still continues to see Ukraine as a brotherly nation.