Why is Doraemon said to be an existence that can touch people's hearts?

In Volume 32 of "Doraemon", there is a story called the reconstruction of a destroyed hotel. During a run away from home, Nobita accidentally entered an old hotel called this house. Later, Nobita and Doraemon used various props to help the hotel owner attract guests. At the end of the story, Nobita realized the mistake of running away from home. The innkeeper's son did not want to inherit the family business and wandered outside. He was also affected by the props and came to the cat and returned home.

Nobita and the Iron Man Corps have always occupied a special place in Daluo Amon's novels in past dynasties. Li Lulu's self-sacrifice, and her rebirth and reappearance outside Nobita's classroom window, are among countless famous scenes throughout the series, and are deeply moving. However, what many people don’t know is that after the serialization of this book, Fujiko made a lot of additions and revisions during the single-line editing process. So there are a lot of differences between the single editions we see now and the originals serialized in magazines.

Nobita’s history of space exploration is different from the previous two examples. It's not a hidden element, but I don't think everyone is thinking in this direction, so I'm putting it in this answer. When I was a child, I read a long novel "Exploring the History of the Universe", and it didn't leave any special impression except for a sharpshooter Nobita. While the end of the history of exploring the universe is also a touching scene, it doesn't feel quite tear-jerking compared to the more shocking endings of the Iron Man Legion, Lilulu, and the Undersea Ghost Rock City.

However, later in the old animation, as Ed's "anger in his heart" sounded, he suddenly realized that a big teardrop had been ignored intentionally or unintentionally: Koya and the Earth, the relationship between time and space. The speed is different. A day on Koya lasts only one hour on Earth. This means that the final result of the separation between Nobita and the brothers Luobu and Kram is not only a long distance in space, but also a long distance in time. Is there anything else you want to say about this issue?