So many ea created by martingale system, and most of this type ea usually will fail eventually, so if relying on ea also need backtest then forward test and also sometime ea created with expired date and need to updated, usually this ea is product with cost to buying so as seller also they want to get income from selling ea
It is true that continuous updation is required in ea’s so as to cope up with the changing market conditions. EA can prove helpful but a trader must not completely rely on it, manual observation of trades is still required.