Its seems like Korach is very concerned about Middas HaGa’ava, and he cannot tolerate (his imagined) Ga’ava of Moshe and Ahron. Ga’ava was precisely Korach’s own problem, like Moshe told him: רַּב לָכֶם בְנֵ י לֵוִי טז ז You seek for too much, sons of Levi, and: וּבִקַּשְׁתֶם גַּם כְהֻנָה טז י Will you now also demand the Kehuna? etc. This is a common fallacy in human nature. If you are critical and you notice the Chesronos of others, you should suspect that the Chisaron you see is exactly your own problem that YOU should be always working on, instead of being busy "solving the world's problems".
In Novardok they taught me that it’s your lifetime job to sit on yourself ("לִ יגֶ ען אוֹיף זִ יךְ )" יוֹמָם וָלַּיְלָה day and night and try to improve yourself! This is why Dovid HaMelech was so great (like he said: וְחַּטָאתִי נֶגְדִ י תָמִיד תהלים נא ה my sin is before me always) and this brings a Bracha to the entire universe, since: יָחִיד שֶׁעָשָה תְשׁוּבָה מוֹחֲלִין לְכָל הָעוֹלָם כוּלוֹ יומא פו ב Even if just ONE person does Teshuva, the entire world is forgiven. וּמַּדוּעַּ תִתְנַּשְ אוּ “Why do you elevate yourselves” is exactly Korach’s own problem. He was an overqualified person, with greatness in Torah and Ruach HaKodesh and very rich. (Gemara).
