Savior Schnapps vs Save and Exit

Just started this without playing the 1st and not sure I understand the risks of using the save and exit vs the potions. I’m aware save and exit rewrites itself but why would I be wanting to open an old save file anyway if I’ve made progress…. Are savior schnapps mostly about save scumming if a decision made a few hours earlier had an unintended consequence you wish to rewrite..? Or are there other reasons schnapps is a better way to save (other then then short time to relaunch game)