Having just watched Ken Burns' The American Revolution and having gone back and started watching his Vietnam series, there's definitely some comparisons to Ukraine to be made (a lot to be made to the Revolution series, even if it was about our founding, still some great comparisons to be made). As one of the historians on the Revolution series said, and as many other historians have said and several of us have mentioned the quote in this thread, Washington realized he didn't have to win, he just had to not lose. Britain was still heavily in debt from the Seven Years War, and with France and Spain entering, it went from them trying to take the North American colonies to them running the risk of losing a lot more than those colonies (including the Caribbean colonies, Canada, etc.) and the British public getting worn out. Similar in Vietnam - they didn't have to defeat us (and arguably couldn't in a stand-up fight with our air power), but they just had to outlast us (or rather the American public's support).
Same for Ukraine. They don't have to win the major battles, but when Russia dips into their gold reserves, when they shut down exports because infrastructure was knocked offline or sanctions shut them down, when they have to leave oil & gas infrastructure because Ukraine keeps taking out air defenses elsewhere faster than they can manufacture them, that's Ukraine winning battles that aren't on the battlefield.