Although the showdown ev is slightly flawed in talking about what you "should" win, because for example say you
bluff the turn planning to bluff the river, but you hit top pair on the river and simply check behind having no reason to bluff. The money went in when you were behind, therefore PokerEV says you were lucky when really you were getting the money if you hadn't hit as well.
But if you just use all-in ev (which pokerEV does have), this is independent of any decisions, because it only calculates how much you should have won when all decision-making was done and the only variable is which cards come.
And of course both of these ignore things such as set over set, opponent having top/bottom of their range, etc. So although these graphs can adjust slightly to show how much you "should" have won, none are entirely accurate. The only way to know how much you SHOULD have won is to play each hand where each card comes on each street against each opponent, and then average them all out. See you in like a million years.