The world before smart contracts was one that was fraught with uncertainty. Legal contracts, even simple ones, need not be followed, and the cost of recourse using most legal systems was and is extremely expensive, even in countries where the legal system is not corrupt. In many areas of the world, contracts are barely worth the paper they are written on, and are usually enforceable only by parties with substantial political or financial power. For weaker actors in an economic or political system, this is a terrible and unfair set of circumstances.
The issues that we mentioned previously come primarily from the human factor. As long as a person is involved in the enforcement of a contract, they can be corrupt, lazy, misinformed, biased, and so on. A smart contract, in contrast, is written in code, and is meant to execute faithfully no matter what parties are...