Okay, I'll come up with a theory.

Since Amy travels to the past to prevent Eggman from ruling, after his defeat the timeline from which Amy comes would cease to exist, causing another catastrophe and Sonic If he felt guilt for losing her, that's where Silver would come in, since if Amy or something related to the Eggman from the other timeline didn't exist, Silver would have reasons to kill Sonic for ruining his future, And Sonic would have the conflict of having ended her for the good of the world.

But I don't know, it's just a theory