Yes, it depends on the components. You normally use more components, such as 20 or 30. Here's a modified script that reads a selection of the most popular ETFs from an asset list in the Strategy folder (both attached).

Your result is also relatively untypical. The typical result that I get with most portfolios is either a much higher profit with the red max return line, or a lower profit but a much better Sharpe ratio with the blue minimum variance line. You can see that with the attached system. For live trading you would normally use the minimum variance version, even though the absolute return is smaller than 1/N. Do many experiments with other ETFs!