The starting point of Jing Ke's stabbing Qin was personal enmity, in order to repay the kindness of the prince. Besides, he is a ranger and is willing to do these things. Changing history is the objective effect of his behavior, which is beyond his control. At that time, people were not as conscious as the assassin in Hero. At that time, people had no concept of "the world" at all. A man with a sense of peace is a philosopher and will not become an assassin. If the Qin Dynasty succeeds, one possibility is that the Qin Dynasty is very powerful, which can stabilize the situation and elect a new heir to the throne. However, this dynasty will eventually perish, and we can refer to the example of Qin Ershi. Another possibility is that the Qin Dynasty collapsed, the remaining vassal states that were destroyed or not reappeared, and a monarch unified the whole country. That period of history has been lengthened or shortened, which has no influence on us now, just listening to a few more legendary stories.
The reason why Jing Ke stabbed Qin was widely spread was because of his tragic color and magnificent character, rather than his attempt to shake history. The assassination of Qin is not for fame, but for profit, or both.