https://en.wikipedia.org/wiki/Spirit_Airlines#2022_to_2024_a...
Instead of giving two smaller airlines a chance to work together and compete against the "Big Four", denying the JetBlue merger all but guaranteed that Spirit would have to file for bankruptcy.
The company's assets are worth more than the company itself so I wouldn't be surprised if it simply liquidates with the result being no fares (because no Spirit airlines), no seats (because no Spirit airlines), and millions of customers with less of a choice (because no Spirit airlines).
The judges ruling was uneducated and poorly based, especially considering how the big four got to be so big. It was politically motivated to make the party/gov look good, but the long term results were good for nobody. I lost money betting on the merger, it makes no sense it got blocked.
Good customer service counts for a lot, it's not just ticket prices, otherwise Spirit would not be having these financial issues.
And even with that, they're losing money and going bankrupt. The big 3 carriers in the US are propped up by their loyalty programmes which are surprisingly profitable; Alaska is the only other carrier doing good and expanding. Everyone else is struggling in some form.