The Star Spangled Banner began its life as a poem. The original title of the poem was "Defence of Fort M'Henry," written in 1814 by slaveholder Francis Scott Key.
The music, added later, was lifted from a British tune "The Anacreontic Song." It was the theme song of a London drinking society.
The lyrics of the third verse include the lines
"No refuge could save the hireling and slave
From the terror of flight or the gloom of the grave."
The latter reference is SPECIFICALLY to black American slaves who fought for the British in exchange for a promise of emancipation. By and large that promise remained unkept and the slaves were abandoned by the British at the end of the war.
Although the United States had no official national anthem for most of its history "Hail, Columbia" was commonly used through the 19th Century.
"My Country, 'Tis of Thee" was also frequently used for official purposes; ironically it's music ironically lifted from the British national anthem.
Not until 1931 was the Star Spangled Banner officially designated the American national anthem. And even then many groups objected to its selection.
In other words...it's just a song folks, and one with a long and complicated history. It's a song George Washington NEVER heard, a song that didn't exist during the Revolution, wasn't the national anthem during the Civil War and WW1, and includes some questionable lyrics.
Nobody ever died for that song...or even the flag. They fought and sometimes died for their homes, their families, their system of government, their rights...including the right to peacefully protest.