Helix I think there is no final truth. The only important part is to have that in mind making decisions.
Also important to have in mind: In the end backtesting isn't forecasting. The strategy that worked for several years could stop working tomorrow.
You could make a lot money just by luck with a strategy that would have ruined you in the past 😃
The market doesn't behave in any way reasonable. For example many coins out there are totally trash in my eyes. Any coin for example that uses proof of work has no future in the long run. For environmental reasons, speed and so on. Any coin that isn't quantum proof too. But they are traded. The current economical crisis / danger should have let to people buying cryptos to save their money. Even horrible news about a coin often doesn't even affect it. Bitcoin (proof of work, very slow) leads the whole market 😃 You see? You got bots trading with bots and people that trade based on greed not knowledge.
Edit: Just realised that sounded very dark 😃 That message is not "stop trading" or its "only luck". But i feel its important to see the big picture, to make the best decisions and being able to react. You need to find a balance between the rational and intuitive side of trading.