You can make excess return without predicting the future. There's just two ways when you reduce it enough:

1. Time the market well. Buy low and sell high. This is usually where technical analysis sells itself (and generally fails in the real world)
2. Buy above-average, higher-quality assets that will perform better over time.

Technical analysis, as packaged and sold on the internet is mostly bullshit. But there are some persistent edges, if you're disciplined with your timeframes and take a broad approach.

For example - someone telling you to use moving averages to try and time a particular stock - that's a losing bet. But there is a measurable edge in buying the stocks with the largest deviation between moving averages (eg. measure the spot price's deviation from the 10DMA, and buy the top 5 stocks making the deepest lows, and sell them the next day). Of course, this has limitations too, and will get you killed in certain market environments (strategy goes from excessively profitable to money-losing).

There's a world of difference between the way charlatan books describe technical analysis, and the way professional quants use some of the same concepts.

Ideally, you blend some pricing factors (analogous to technical factors) with fundamental factors (high quality assets) to build a portfolio of things that higher quality than the overall market and are on sale relative to other assets.

Needless to say, this is the hard way.