After 5 years of algorithmic trading I can state the it is easy to acheive 50% annualized or profit factor 1.5 in backtests.
They call it overfitting.
It is the reason forums are full of attractive backtests but almst no attractive live trackrecors.
If someone had an EA printing 50% per year there would be no reason to sell it.
Maybe that is a good strategy, but there are many good strategies that lose 20% per year trading live, those that make 10% per year are very few.