One of the things that interests me the most about the original Winter Soldier arc is just how personal the intention behind Project: Winter Soldier was.
When I read issue 5 of Brubaker's run for the first time, it seemed almost like it was just a filler issue to pad out the arc and introduce some exposition about the new, shadowy villain. One of those many war flashbacks, because the run had been focusing pretty heavily on events of the past. Then, later issues completely recontextualized it. Not to say it's not complete exposition, because it is, but there's a lot more weight to it on a reread.
For as much as a tragedy this is in-universe, the reckless loss of life, it sort of just seems like a typical villain backstory/motivation. Then you get a few issues further in the arc, and you finally learn who the Winter Soldier is.
Honestly, I find it a little strange that Karpov only appears/is named a handful of times, because issue 11 very firmly establishes him as the Winter Soldier's primary architect. It also very firmly establishes that, while there is a lot of value that the KGB/Department X got out of the Winter Soldier, one of the most pressing reasons that they even turned him into their assassin was because Karpov had a grudge against Captain America. Not in the broader "people got killed because of your intervention/the intervention of superhumans like you" sense, but specifically because Captain America "shamed" him and made him feel inferior.
Essentially, Codename: Winter Soldier exists as a means for Karpov to heal/put right his wounded pride. Forcing this American icon to serve and kill for those who were offended by him (those who later became his nation's enemy), was a more symbolic gesture than it was a practical one. On top of that, one of Karpov's final orders before his death was that the Winter Soldier be decommissioned, turning him into nothing more than an "abandoned experiment."
Bucky is, of course, a talented assassin as the Winter Soldier, but because he's artificially loyal to Department X and not naturally, he is not an efficient agent for them by any means. Ensuring that he stayed stable was a constant concern for those who wanted to use him as their weapon. They only started putting him in cryogenic stasis around 1958 (or 1957 depending on the source, but 1958 is the more recent citation), and it's approximately the same for the frequent memory wipes & implementation.
But frankly, no matter how talented the Winter Soldier is with espionage and murder, the only thing that made him a truly valuable investment to the KGB was Karpov's grudge. I suspect that if Karpov hadn't ordered him decommissioned, Department X and the KGB would have stopped reviving him and sending him out to do their work anyways; realistically, the constant memory wipes to curb his "instability" must have been expensive (time-wise and resources-wise), as would have been the cryogenic stasis and maintenance. At some point, the cost to keep him serviceable to the KGB would have outweighed his value as their operative.
(And that is, of course, not even touching on the political state of the Soviet Union in the late 80s.)
Even later on, when Aleksander Lukin revives Bucky to retrieve the Cosmic Cube from the Red Skull, it is both because he was Karpov's protege (following his will), and because he is making an enemy of Captain America and SHIELD with his mission. It all returns to that same old grudge and the symbolism it allows for. Lukin sends the Winter Soldier to go out and kill Jack Monroe/Nomad (because he had been one of the people to take up the role of Captain America's Bucky when Steve and James were presumed KIA). Using the Comic Cube, he plagues Cap with visions of the day that he and Bucky died/went into the ice. He has the Winter Soldier kidnap Sharon Carter, who would- and did- recognize him as Bucky, and who would tell Steve about it.
(Do note how one of Lukin's intentions involve having Steve "suffer" for a little while longer, and how he assumes that the Winter Soldier's "personal feelings" are the reason he suggests killing Steve, when, to a brainwashed Bucky, it's actually just a matter of practicality.)
With the Winter Soldier, his greatest value to his superiors is consistently in the fact that he was affiliated with Captain America. Of course, he offers them value in the sense of being a tremendously talented assassin and covert agent, but that's not a resource they were exactly hurting for (the Red Room, for example). Arguably, he was a valuable lab rat too, with Project: Winter Soldier partially being a prototype for the Red Room and Wolf Spider programs, but *that* was done to take his undying loyalty and turn it into something malleable.
