Like, you die and then you just load the save and everything is back to normal. I think there should be a gold penalty. Because dying doesn't matter anymore, I just save before I go into a dungeon, if I die, I just reload and start again.
What do you think?
You answered your own question. Play that way, others can save when they want.
I wouldn't do dead is dead because a) I have other things to do in my life and

the combat system is still too cheap. You can end up a victim of bad play mechanics.
As for realism of design, I agree that it feels dumb to have a game where you pretty much can't get through an area playing well, that all traps are lethal and you will die when you trip them.
Certainly you play more realistically when you aren't relying on saves to back you up or abuse the mechanic by taking on long odds and doing it a hundred times until you impossibly win.
Knowing you have the save crutch can feel less immersive but knowing you can be screwn By bad mechanics is worse. Rember how frustrating racing was in gta4 when you had to load, get brucie, get to the track, race and lose because the cars handle like they're on ice and you lose control? It doesn't even feel like you lost because your skills aren't up to it, it feels like bad controls, bad design. And playing it a dozen times to beat it does not feel like realism.