Another factor can be blamed on the Musicians Union which went on strike on August 1, 1942. No agreement was made until September of 1943 when Decca Records made an agreement. Blue Note followed in November, and other record labels later that year. However, most swing bands were signed to Columbia and Victor Records. These two record labels would not settle until November 1944, a full 27 months; that's over 2 years in which no swing bands from these two labels were published.
However, singers were not part of the Musicians Union, and thus they were not on strike and could be recorded. The result of this was that singers became popular and the bands, particularly swing bands, diminished in status.
Additional factor was a cabaret tax in 1941 causing clubs to pay 30% of their ticket sales in taxes. This meant that bands that were hired by the clubs had to be smaller and cheaper, something swing bands — especially swing jazz big bands — could not easily adjusted to.
A new jazz sound, Bebop, began to grow in popularity as did the inexpensive rhythm & blues bands.
Finally, with the end of the what became known as World War 2 and of what became known as the Great Depression, people did not want to be reminded of either of them. Swing, which became popular during the depression and was so popular when the war started, became a reminder of those bad years. With the bad memories and the bad emotions that swing music brought back to mind, people simply stopped listening.
With that the Swing Era was dead.
Very soon, partner dancing in general would be dead, too. East coast swing, the dance that replaced Lindy Hop at the end of the Swing Era, as well as dances like the Waltz, Foxtrot, and others would die off when in the early 1960s, Chubby Checker's "The Twist" killed partner dancing.