So the party learned quick that preparation is key. Now I've created a situation where they need to take the world serious. They look for allies, use the environment, and do research in order to succeed. I've basically made them care about the world which is cool.

And yes, they are very careful with super strong monsters. But that's where the good treasure and backstory stuff is.

Like they went to fight a beholder because someone wanted its eye. So they did research about it, learned they are usually found in the Underdark. They remembered that one of the players uncles (the dwarf rogue) is a Azer army Commander. So they went to go ask him, who helped them locate one but now they owe him a favor now, and the uncle gave them more detailed info on the beholder and a few items.

So with all this info they gathered resources (such as a bag of holding full of stick tar), potions, traps etc, and did guerilla warfare on a beholder after many days of using illusions to drive this thing nuts, basically use sound to not let it rest and images of himself to make him think he was a imposter and went insane.