The most obvious benefit of specialization and trade is that they allow us to

The most obvious benefit of specialization and trade is that they allow us to: Consume more goods than we otherwise would be able to consume

When we do specialization, we could produce the goods that provide competitive advantage for us so we can produce that goods in a huge amount.

After that, we can trade the goods with other goods (which gives competitive advantage to other country) and trading countries could consume goods on a huge amount.