It can be difficult for new airlines to compete with established airlines like 
Delta Air Lines, 
American Airlines, 
United Airlines, and 
Southwest Airlines. While these airlines may have already claimed most of the busy and profitable routes, there are still crumbs to be had. Low-cost and ultra-low-cost airlines now make up around 34% of the US airline market share (around average for the rest of the world). In 2021, the United States saw two new startup airlines enter the market: Breeze Airways and Avelo Airlines. These small low-cost carriers have been carving niches out for themselves that have been largely overlooked by the larger legacy airlines. While legacy carriers sometimes have a commanding grip on the slots and routes at large airports (e.g., United at Newark Liberty International Airport), these startups are targeting smaller regional airports.