Go is not a business oriented language. To be a business language, you need a decimal data type built in (or in the standard library), that doesn't make you go through hoops like this:

    total = new Decimal(principal);
    total.mul(1.0 + interest);

In other words decimals support the same operations as the rest of the language's numeric tower. Go doesn't have this.

Go is a networking language. It's good for writing microservices and network protocol clients and servers. That's about it.