Unless you've taken a long airplane flight while wearing good noise cancelling headphones, you can't understand why they are so important. That's because your brain will trick you. It will convince you the jet engines aren't THAT loud.
But they are.
If you wear noise cancelling headphones on a flight, then take them off during the flight, you will be shocked at how loud the engines are. It is frightening!
And there's a price to pay for all that noise. Your ears will, over time, be damaged. Plus without ear protection you will arrive weary and somewhat "beaten." This article in The New York Times does a very good job of describing the impact of noise -- and the benefits of noise cancelling headphones:
https://www.nytimes.com/2019/05/07/travel/the-pros-and-cons-of-noise-canceling-headphones.html
The one downside the Times points out is price. Since the best selling NC headphones sell for over $300, they question the value equation. The good news is that ZVOX AV50 noise cancelling headphones cost half (or less) what the best-sellers go for. Plus you can try them for 60 days and return them if you don't love them.
So do you ears a favor. Try them.