Why terms&conditions/rules&regulations or Government/Private business deal terms are difficult to understand?

If I take a loan to buy a car,the voluminous terms&conditions is very confusing,.
If I buy a property I am at my wit’s end to decipher what they say in the paper.
Similarly any court dealing runs into many pages.
Once I repaid my 5-year housing loan in three years.
For this they penalized me by a considerable amount.They call it pre-payment charges.

Why they are not straight and simple.