The reason the tzaddikim of today are rich whereas in previous times most of them were poor and poverty stricken, is hinted at in the Mishnah: Whoever fulfills the Torah in poverty, will ultimately fulfill it in wealth (Avot 4:9).
For the tzaddikim of today are the very same tzaddikim that lived in previous times—in the mystery of reincarnation. They already fulfilled the Torah in poverty, and therefore now merit to fulfill it in wealth.
הַטַּעַם שֶׁהַצַּדִּיקִים שֶׁבַּזְּמַן הַזֶּה הֵם עֲשִׁירִים, וּבַזְּמַנִּים הַקּוֹדְמִים הָיוּ רֻבָּם עֲנִיִּים וְאֶבְיוֹנִים, זֶה מְרֻמָּז בַּמִּשְׁנָה (אבות פ"ד): כָּל הַמְּקַיֵּם אֶת הַתּוֹרָה מֵעֹנִי סוֹפוֹ לְקַיְּמָהּ מֵעֹשֶׁר,
The reason the tzaddikim of today are rich whereas in previous times most of them were poor and poverty stricken, is hinted at in the Mishnah: Whoever fulfills the Torah in poverty, will ultimately fulfill it in wealth (Avot 4:9).
וְהַצַּדִּיקִים שֶׁבַּזְּמַן הַזֶּה הֵם הֵם הַצַּדִּיקִים שֶׁהָיוּ בַּזְּמַנִּים הַקּוֹדְמִים בְּסוֹד הַגִּלְגּוּל, וּכְבָר קִיְּמוּ הַתּוֹרָה מֵעֹנִי, עַל כֵּן זוֹכִים עַתָּה לְקַיְּמָהּ מֵעֹשֶׁר:
For the tzaddikim of today are the very same tzaddikim that lived in previous times—in the mystery of reincarnation. They already fulfilled the Torah in poverty, and therefore now merit to fulfill it in wealth.