Which is better, American or Delta?

Choosing between American Airlines and Delta Air Lines comes down to network, service reputation, and loyalty program preferences, because both are major legacy US carriers with global networks. American is a founding member of Oneworld alliance and has major hubs in Dallas-Fort Worth, Charlotte, Miami, Philadelphia, Phoenix, and Chicago, with strong routes to Latin America and Europe via British Airways and Iberia partners. Delta is part of SkyTeam alliance with hubs in Atlanta, Detroit, Minneapolis, New York JFK and LaGuardia, Seattle, and Salt Lake City, and is known for strong transatlantic routes via Air France-KLM and Virgin Atlantic. In recent years, Delta has consistently ranked higher than American in JD Power customer satisfaction, on-time performance, and baggage handling, and is often praised for slightly better customer service recovery during delays. American often has more low fare options and a larger fleet. For frequent flyers, Delta's SkyMiles program never expires but is often criticized for higher award prices, while American's AAdvantage has more predictable award charts for partner airlines. If you live near a hub, that airline is usually better for you due to nonstop options. Many business travelers prefer Delta for reliability.