Why do you purchase anything? Because you value the good (or service) more than you value the money. Why does the seller take your money for their good? Because they value the money more.
Any voluntary transaction benefits both the buyer and the seller.
Is your standard of living improved by the coffee you drink in the morning before you go to work? Is that changed if the coffee is grown in another country?
Come on, basic microeconomics.
I grow vegetables; you are a carpenter. I want your service; you want my vegetables. We exchange money and we both feel like we came out ahead. I get that. Free exchange of money for goods and services is a good thing.
Global trade:
There is a peasant in China with a life expectancy of 40. He makes $1000 a year, with no benefits. He lives next to a hellaciously polluted river. He works in a dangerous factory manufacturing TVs. You, on the other hand, live in a nice American suburb. You lost your manufacturing job, and you are living on unemployment right now. But your standard of living isn't too bad -- you just bought this super cheap TV from China. It's amazing how they can sell this stuff so cheap and still stay in business!!!!
American workers are competing with people who have wretched lives. They work cheaper than we do. Which is why they have jobs and we do not. It's becuase we send our money overseas and we tell ourselves that this is making us rich. Hey! Look! I got a TV!