Eliminating the need for synchronization isn't the only benefit of high tension DC power lines. DC is also sometimes used for long-distance transmission lines

Eliminating the need for synchronization isn't the only benefit of high tension DC power lines. DC is also sometimes used for long-distance transmission lines to avoid hysteresis losses. The downside to DC is that voltage step-up and step-down equipment is more complicated/expensive and (at least generally) less efficient. In high school, I was told that a lot of the power for Minneapolis was sent over high tension DC lines from coal power plants in the neighboring Dakotas for this reason. This was part of the lesson about how the lakes in northern Minnesota had very little pH buffering capacity due to limestone being scraped down to bedrock by glaciers and therefore being particularly sensitive to SO2 emissions from coal power plants in the Dakotas, but most of the electrical demand for that power also coming from Minnesota.