Those simple strategies you undermine are enough for you if you work on yourself. I was shocked when I realised someone bought a trading strategy for $3,700...oh my God!

And guess what, it failed him, what a waste!
A trader friend of mine laughed when I told him that I concentrated more on oversold and overbought levels, to him, those concepts were far too simple for it to be able to yield any profit in trading. He was putting his focus on complex things because to him, your strategy has to be as complex as the charts look. While he is still struggling to understand those complex concepts surrounded by many noise, people with the simpler strategies that are straightforward to understand are making progress already with their trades and having positive returns.
Don't let anyone mistake you, both simple and complex strategies can work, so long as you know what you are doing. Why must a strategy be complex? It's not necessary. The issue there is that the more complex the strategy is, the more problematic it can be, and the simpler the strategy is, the better.
Nonetheless, I like strategies to have the important information needed from them. Whether simple or complex, a good strategy should know how to:
1. Spot the trend
2. Read the market pattern (price action), and
3. Detect the overbought and oversold conditions of the market.