Why are there so many different trading strategies?

I’m talking specifically about trading, not investing. I’m new to trading and I feel the need to find a fool-proof strategy before I start buying and selling anything. However, it seems that no matter where I ask, everyone has a different opinion on what the best strategy is. Some say news headlines and breaking news are everything, while others say that news means nothing and that all you should focus on is trends and price action. Why isn’t there just one way that people have found works best? If certain strategies really don’t work, then wouldn’t it be obvious? And anyone using these false strategies would be clearly proven to be wrong because of their low accuracy? Why do some people claim that their strategy works so consistently while others say that the same strategy doesn’t work at all? What really affects stock prices and why do people seem to be so divided about it?