I got an inquiry asking: "I am interested in any thought you would be willing to share about why we were willing to sacrifice to come to this earth. I don't think that this earth is the only place in all of creation where one can learn to return to the presence of the Lord, so what is the purpose of the righteous in the preexistence coming here? Why not take an 'easier' route and go to a different terrestrial mortal state?"
Because we saw great benefit in coming. In fact, the opportunity was greeted with shouts of joy. (Job 38: 4-7.) Perspective from here is not the same as perspective from above. There is a required opposition in "all things." (2 Ne. 2: 11.) To ascend you must first descend. The path to the highest state runs through the lowest. (See, e.g., Moses 1: 18-20; see also JS-H 1: 15-17.) You will not see the Father and Son (D&C 76: 20-21) without also seeing the fallen angel cast out for rebellion (D&C 76: 25-26). Nor will you behold the Celestial Kingdom (D&C 76: 50-58) without also seeing the horror of outer darkness (D&C 76: 44-48).
To comprehend you must become acquainted with both glory and darkness. You cannot receive the one without also the other. Joseph put it this way: " Thy mind, O man! if thou wilt lead a soul unto salvation, must stretch as high as the utmost heavens, and search into and contemplate the darkest abyss, and the broad expanse of eternity—thou must commune with God." (TPJS, p. 137.) You do not get to behold glory without also beholding the darkest abyss. There is a parallel to comprehension, a symmetry to understanding.
You came here to increase your understanding of truth, and to broaden your capacity to appreciate what is good. For that, you wanted and now are receiving, exposure to the brackets which allow your comprehension to expand.
You will eventually leave here. But you will depart with an expanded capacity which could come in no other way.
Read the perils through which Abraham passed, and know this was necessary for him to become the Father of the Righteous. There is no path back to heaven apart from walking through the valley of the shadow of death. Your understanding of eternal life will come from suffering death. Your appreciation of eternal glory will come from having been first composed of the decaying dust of this earth.
You wanted this. You shouted for joy when it was offered.