it's hard to believe that any strategy can work for a long period, but like in everything else I believe there're exceptions here, so probably some people are doing the same thing for years, and that is still profitable for them!
There are very very less possibilities for same strategy to be working for years because market conditions and market fluctuations are improving and varying over the time which makes most of the technical analysis need to be improved or modified according to different market conditions. So, more of technical strategies will not work for long periods in crypto markets.
It would be foolish to think that everyone follows the same strategy, it would be better to say that we all have the same goal, to make a profit! But how we get to that profit is a different story for each of us!
I don't agree that it is not kind of foolishness because we are all working for making profits by buying at cheaper levels and then selling at higher levels which makes some people are assuming like we are all into same kind of strategy; and I am not seeing any wrong with that.