at some point scientists have to settle with the fact that it is now endemic. We don't call the flu 'flu-2021'
For example, the 2009 “swine flu” pandemic virus is called H1N1-pdm-09 (or just H1N1/09) in literature.
Curing the Flu is a solution. The public wants this, not a flu shot, no matter how impossible the task is. A flu shot every year is just band-aiding the problem, and redelivering said problem every year.
But, we’d also need to rout out all the reservoirs of flu virus in agriculture and nature that have the potential to jump species back to humans. That’s a lot of ducks, chickens, pigs, whales, horses, seals, etc to vaccinate or cull.