The Boeing 747 has been replaced by more fuel-efficient, long-range twin-engine widebodies, primarily the Boeing 777-300ER, the Boeing 787 Dreamliner, and the Airbus A350. While the 747 had four engines, these modern replacements use only two, which significantly reduces fuel burn and maintenance costs while offering similar or even greater range. For pure capacity, the Boeing 777-9 (777X), which entered more widespread service by 2026, is the closest direct successor, carrying 400+ passengers with "Queen-sized" dimensions but 20% better efficiency. In the cargo world, the 747-8F is still highly valued for its nose-loading capability, but even there, the Airbus A350F and Boeing 777-8F are becoming the new industry standards. The era of the "four-engine giant" ended because twin-engine technology became powerful enough to safely cross oceans (ETOPS) without the massive fuel penalty of the 747.