Why isn't there still any water-proff laptop yet? How impossible is it?

I'm pretty sure rugged military grade laptops are waterproof, dust proof and shock proof, but they are bulky and heavy, so everything is a compromise.

I'm pretty sure the "ToughBooks" are water-proof.

Edit: apparently close, but not exactly: https://www.bobjohnson.com/blog/are-toughbooks-waterproof/

Waterproof phones and watches exist. So, the tech exists.

For a laptop, the main obstacle is due to the hinge / interface between the base holding the keyboard and the screen if one were to go with the traditional design of a laptop.

As others pointed out, rugged laptops come close.

Search the web for "rugged laptops".