What are you talking about? The flu has not disappeared. In fact, in the very post you responded to, I mentioned how the flu led to 53,495 deaths last year.
You can mention whatever you want, but you can't tell the truth.
Flu viruses are constantly changing so it’s not unusual for new flu viruses to appear each year. During the 2020-2021 flu season, there was very low circulation of seasonal flu viruses. During September 27, 2020–May 22, 2021 in the United States, 1,899 (0.2%) of 1,081,671 clinical samples tested were positive for an influenza virus (713 [37.5%] influenza A and 1,186 [62.5%] influenza B).
CDC - Flu Activity
Imagine, the flu, that was causing seasonally between 50K and 80K deaths, had registered less than 2000 cases for whole flu season.