One of the main accomplishments of Melech Hamoshiach is “מקבץ נדחי ישראל” – to return all of the Yidden to Eretz Yisroel (after he builds the Beis Hamikdash).
There are many mitzvos that are dependent on all Yidden being in Eretz Yisroel (כל ישראל יושבים על אדמתם) and we have to wait till Moshiach comes to fulfill them.
ראה רמב”ם הלכות מלך המשיח רפי”א
Rashi tells us (נצבים ל, ג): Kibbutz Goliyos will be tough, but Hashem will כביכול grap each Yid by the hand and shlep them back to Eretz Yisroel.
May this happen speedily in our days!
בניסן נגאלו ובניסן עתידין ליגאל
(P.S. Last Sukkos, all Yidden living in Eretz Yisroel said in musaf “מפני חטאנו גלינו מארצינו”… vidal)