Cholesterol is essential. It's a key building block for the cell membrane, it's a precursor to multiple hormones and necessary for producing vitamin D and bile acid. 2% of your body is cholesterol.

And the liver creates cholesterol. It even senses and reduces cholesterol output when we have too much. Except saturated fats interfere with this process.

Your body is 50% water and you can still die from drinking too much.

To the extent that this is true, it’s irrelevant: your body has many things which need to be within certain ranges for health. Salt, water, oxygen, etc. are all vital but too much or too little will make you dangerously ill.