One is for personal use. The other is for ordinary use. Which type are you?
Every time one of my favorite bands releases an album, I purchase the physical CD. Then, I play the entire album in a CD player, headphones plugged in. Eyes closed, no bathroom breaks. Non-stop. I let the sounds penetrate my brain. At the end of listening to the album completely, my mind is renewed. Listening to hi-fi music was and is important to me, thanks to headphones.
Headphones are a bulky device to carry around. However, when you use it, music does not escape your ears. Whatever noise is happening around, you cannot hear it. Headphones makes it personal. It engages you. You and music. Isn’t the act of listening to music all about enjoying sounds?
On the other hand, earphones are compact, can be carried in your pocket wherever you go. Ideal for working out at the gym. Some use them at work to keep themselves from falling asleep. Way easier to put on. You hear the music, same as headphones, except a slight cord movement and now you hear whatever noise is around you. It disrupts the experience of listening to music.
Masses tend to buy products that are easy to use, comfortable and in doing so sacrificing quality. In the same way, people are watching tv shows on smart phones screen rather than viewing it on the tv screen which is how it is intended to be experienced. Content is being ingested either way but how it is being consumed is different. One in a personal manner, the other ordinarily.
I own earphones and have seen a couple of movies in my iPhone but I am a headphones type of guy. My reasoning: people dedicate years to create quality content through music, paintings, films, etc., piecing it all for you, the consumer. The least we can do is immerse ourselves to the experience they share with us in the best possible way.