Flaggers serve an important function. They tell you when it’s safe to race and when it’s not. The debris flag is a warning that there’s something unusual about the track surface ahead. It could be oil, dirt, sand, blood, etc. Ignore at your peril. Note, in the following clip, the audio is unfortunately out of sync.
It’s too bad this guy wrecked his chariot. The car was clearly one of the fastest on track. The debris flag was out, and by ignoring it, he ruined the car and the race.