The American Customer Satisfaction Index - which has been doing airline satisfaction scores since 1995 - doesn't show United to be a threat in its report of a few weeks ago.
Emphasis mine.
Despite a 4% leap,
United sits in the bottom three with a score of 70, only besting Frontier (64) and Spirit (63), which see 3% and 2% climbs, respectively.
Delta also rises 1% to an ACSI score of 75, making it number one among legacy airlines. Passengers enjoy the airline’s many in-flight amenities, including seatback screens, USB ports, and Wi-Fi.
https://www.theacsi.org/news-and-res...avel-2018-2019