Firework displays remain popular because they are a visual and auditory spectacles that bring amazement and joy to many who watch them. You mention “safety risks” but you don’t identify them. Shooting fireworks into a crowd of people would pose a level of risk, that I can agree would be unacceptable, but a firework show performed by trained personnel under supervision from our fire department satisfies me that the risks have been accounted for and been mitigated.
Is it worth it? Is it worth the noise and air pollution? Yes, without a doubt. My own grandfather and father were war veterans. Celebrating the 4th of July, the independence of our nation, was a way for them to remember that the years of sacrifice they made for us had meaning and purpose. We also need to educate our children and not leave them ignorant of facts or history.