I get the OP's frustration - but HoI is a wargame, not an empire-builder like CK2, EU4 or Vicky, so it
should feel different, and if it didn't then people would say HoI4 was EU5 (oh, wait.....

). Rather than lots of little 'war - peace - war' patterns, it's more a 'campaign - buildup - campaign' rhythm instead, where they pay-off is winning.
As others have said, HoI isn't that well suited to a cold war style game - I'd think it would be better suited expanded back to earlier in the 1930s, to allow for more of a build-up, but the 'heart' of HoI is the big broo-ha-ha as the factions beat down on each other for dominance.
I wouldn't say there's little payoff (if you've won - or lost - after a titanic struggle, that's a lot of enjoyment had, with a clear result), but I do think there's value in better 'summing up' the win. I'd love an 'end of war' screen, where at the end of the war, or in 1948, it summed up the state of my nation - how much did the people suffer to get that win (things like how long countries were at different war laws), how many victory points they and their alliance controlled, whether they're the dominant faction or there's two competing factions like there were historically. Did the world descend into thermonuclear war? What proportion of the nation's manpower did the victory cost? There's lots of metrics by which a campaign could be judged more or less successful.
Then, while we're playing, we're not just playing for a binary 'win/loss', but for a far more granular win that the game would be able to quantify for us. It would also make 'short' expansions up to Korea make sense, as it's a few more years to try and get that 'dominant faction' thing happening.