The judge did not approve the the strike. The Teamsters claimed that the company's actions during negotiations changed the status que and therefore the pilots could strike. The company claimed that the strike would cause them "irreparable harm." And the judge found in the company's favor. Along with the idea that the public would suffer irreparable harm. As the judge said, "Imagine Christmas without Amazon!"
And how are the Teamsters supposed to increase pay and benefits? They are in negotiations with the company. Welcome to the Railway Labor Act. They meet with the company and propose something. The company says "No. We'll continue this next month." That's why airline contract negotiations in the US go on for years and years.
Companies exist for profit margins. The question is over what time span?