Neither EMA nor SMA is universally better; the EMA reacts faster and suits day trading, while the SMA filters noise and works better for long-term trend confirmation.
For day trading, the EMA is the standard choice. The 9-EMA and 21-EMA combination is the most common for intraday entries and exits.
Faster reaction to price changes produces earlier signals, which matters on 1-minute to 15-minute charts where delayed signals mean missed trades or poor fill prices.
For long-term or swing analysis, the SMA remains the more reliable option because it filters short-term noise better than the EMA.
Many traders run both: EMA for triggers, SMA for the bigger picture.