I have had the flu vaccine from 18 to so far 43 and have never had a really bad flu at all. I would say the vaccine works using my experience. My wife has gotten it yearly since meeting me (1993) and our 4 children get it religiously. So in a sample of 6 people from ages 43, 43, 14, 12, 10, and 4 with little to no sickness and a wide variety of ages, I would say that the flu shot not only works but is a necessary responsibility for every American to have to ensure that the flu does not spread and actually dies off.
Problem with anecdotes is that they’re anecdotes. I’m also 43, have never gotten the flu shot in my entire life, and if I’ve ever gotten the flu it was so mild it was mistakable for a head cold and I was over it in 3 or 4 days. My 45 year old wife has the same story, no shots, no flu. So my anecdote with no shots and less flu than you says the shots are bad.
In the end we need to know ourselves. If your body has proven to be susceptible to the flu, get the shots, they probably won’t make things worse and might even help. If your body is able to fight it well, don’t get the shots, save it for somebody who needs it.
And we’re never killing the flu off. It mutates too fast, as long as we have to make vaccines against strains and not the whole thing it’ll stay alive because somebody will always be catching a strain other than what they were vaccinated against.