Of course most of the traders are doing this strategy and there's no trader that will buy high and sell low. It's a common sense that a trader will always get for profit when trading. And I don't have any other strategy with trading as this is the most effective and very common way of trading.
There are a bunch of strategy in trading, google is your friend.
I really agree with you there, buying when the price is low and selling when the price is high is a natural way to earn profit on every assets or items that you have. As a business minded person, or as an entrepreneur, it is really the common way to earn. And I dont count these as a strategy because it is an obvious, one of the strategies that I know is on stores franchises where if the asset is in or in demand in that season, we increase the price and equal it to the demand. I dont think that it will be also done to bitcoin, but there are months that the price stability of bitcoin is the same and increasing.