Anyway almost every game have Hardcore mode to counter save scumming
What does that have to do with anything?
If players want to save-scum, they probably aren't playing on hardcore mode to begin with, so the existence won't do anything to those who don't pick that difficulty.
And making hardcore mode the ONLY mode would be a disaster. Many people, myself included, have no interest in playing an 80+ hour RPG where if you screw up you have to start all over. I would not buy or play a game like this if it could only be played in hardcore mode.