The subject you address is very broad and complex, estimated @ladyrebecca. The Spanish philosopher and novelist Miguel de Unamuno wrote a book of essays (one of the main ones in his work) entitled Of the tragic feeling of life (I don't know if there is an English translation), where he deals with the subject, specifically in chapter 3: "The hunger for immortality". As its title says, it reflects that "we cannot conceive of ourselves as not existing", and maintains that we are all animated by "the thirst for eternity". For him this can be partially realized through fame, love, and memory thanks to a work.
And I want to connect this with your first reference, that of the Chinese emperor Shih Huang Ti. He took me to the story by the universal writer Jorge Luis Borges called "The Wall and the Books" (I don't know if you've read it; I'll leave you a link to an English version: https://southerncrossreview.org/54/borges-muralla.htm), in which the narrator fictionalises the two great works of this emperor: the construction of the Chinese Wall and the burning of the library. Curiously, antagonistic actions -construction vs. destruction-, and he associates them with the permanence in the memory of his own people.
I really enjoyed your post. Thank you for your serious work, @ladyrebecca.