This war has been a unmitigated disaster for Russia politically, economically, diplomatically and militarily. But I don't think they at this point have much of a choice. They simply don't have the military and economic resources to win this war and domestically the war is also unpopular. Better to cut their losses now. At least that's my view of the announcement.There has been some discussion here for what is the minimum for Russia to get in order to come out of this strategically , at the very least, neutral.
For me, anything else than Russia getting (annex/puppet/vassal) Eastern Ukraine and South Ukraine is a failure
The costs that Russia has paid are too big for only getting some little territory