I just wished it was not necessary. Iron man should firstly add the thrill permanent decisions and the possibility of actually losing. And secondly it should remove the willpower barrier. Knowing that you cannot possibly ever go back no matter what is (at least for me) very different from having a safety net you could fall back to if you just reason with yourself hard enough.
I was very proud of myself when I restarted a so far very good three mountains try, because I had made a grave mistake I could not recover from. Except of course for restoring the save I had taken three months earlier.
Your decisions still matter.
Reloading a save because you made a mistake is savescumming. Reloading a save because the game made a mistake isn't.
Like the recent attitude bug, where a province bordering an ally getting sieged down by rebels meant they desired your provinces.
It's not a mistake running into that if you've never heard of it.
If you know it exists and still run into it we can start arguing if it's savescumming or avoiding a bug.
I think it is, but can totally see how others would justify reloading an older save.
Not knowing about it and running into it instantly kills your alliance and makes it unrecoverable.
That stuff can throw runs back several decades without any kind of counterplay.
The game expects us to calculate absolutely everything and have very clear and precise plans.
If we as players can't account for a certain event despite having full information it's not us who are to blame.