This only tells half the story. Vaccines are also effective at reducing the severity of the flu, if you do catch it anyhow. For most people (no egg allergies, etc.) there’s little downside risk to getting the shot, and considerable upside benefits (even 12% is far better than 0%).
BTW, if you’re counting on “herd immunity” to protect you — your best strategy would be to attempt to convince everyone else in your “herd” to get vaccinated. Campaigning against vaccines for other people is your worst strategy.
BTW 2, you shouldn’t count on “herd immunity” to protect you.
I’m one of those who cannot have the flu vaccine because of an egg allergy. Fortunately, although I tend to get the upper respiratory tract infections most years, the proper flu is rare. The last time was 1995 in August - late winter in South Africa.