I'm not trying to kill my party, but I also won't stop them from being stupid and getting themselves killed. I design my campaigns like an open world video game. Everything is going on and just reacts to the players. They can find bits of information about things and then act on it, doing whatever they want until they start finding clues about the big bad because I like to try and make it more natural with the characters just existing in the world and not the stereotypical call for adventure a lot of modules and stuff do. But this also means balancing out the world by having the encounter zones being somewhat static. Over here shit is low level, but over there stuff is high level. But like, they will have clues. If they hear the rumors of a Balrog at level 3 and want to go fight it, that's on them.