Why did American f4 immigrants stop moving?

The reason why F4 immigrants in the United States do not move is mainly because the waiting period of such immigrants is very long, and it takes years or even longer to get a green card. Specifically, the number of F4 immigrants has exceeded the annual quota of 65,000, which leads to the continuous delay in the waiting list. At present, the number of people applying for F4 immigration has exceeded 65,000.