The Honest Answer
Most stock alerts fail because they push decisions onto traders at random moments without context, ranking, or preparation. An alert is a single data point (“this stock just did X”) delivered with urgency. A good trading decision requires context (chart review, risk assessment, market conditions) delivered with patience. The format of alerts actively works against the process of good decision-making.
This doesn't mean all alerts are useless. Price alerts on your own watchlist stocks are great. But subscribing to a service that blasts you with 30+ notifications per day? That's not a trading edge. That's an anxiety generator.