No single airline flies everywhere. Not Emirates. Not United. Not Singapore Airlines. The largest carrier on Earth covers roughly 15% of global destinations. The other 85% require a partner.
That's not a limitation. That's the reason airline alliances exist.
There are three: Star Alliance (1997), Oneworld (1999), and SkyTeam (2000). Between them, they connect over 1,000 airlines' worth of routes through codeshares, interline agreements, and shared frequent flyer programmes. A passenger books one ticket, flies three airlines, checks bags once, and earns miles on all of it.
The customer sees convenience. The airlines see economics.
Building a new route is expensive. An airline entering a foreign market needs landing slots, ground handling contracts, regulatory approvals, crew bases, and marketing spend — before selling a single seat. A codeshare with an alliance partner achieves the same network reach for virtually zero capital.
United doesn't fly to Mumbai. But its Star Alliance partner Air India does. United sells the ticket, Air India operates the flight, both airlines take a revenue share. The passenger's United miles accrue. The route appears on United's booking engine. No aircraft purchased. No crew hired. No slot acquired.
That's the engine underneath every alliance.
But the real value is the frequent flyer lock-in. A passenger with 80,000 Star Alliance miles isn't comparing fares objectively. They're comparing fares within the alliance — because switching means abandoning status, lounge access, and upgrade priority built over years.
The alliances know this. It's why elite status recognition is mutual across all member airlines. Your Lufthansa Senator card opens the United Polaris Lounge. Your Singapore Airlines PPS Club status gets you priority boarding on Ethiopian Airlines.
The stickiness isn't the route. It's the tier.
Three alliances. Sixty-two airlines. Over 21,000 daily departures connecting virtually every commercial airport on Earth.
No single airline flies everywhere. Together, they don't have to.