Every Yom Tov is a form of thankfulness. Why is Chanukah officially Hoda'ah (thankfulness) more than any other Chag? Chanukah is a total Yom Tov D’rabanan, which was created by humans. Perhaps this is why the Rambam says: יאה הִ יבָ בִ חַ this is a very precious Mitzva only here. חַבִיבִין דִבְרֵי סוֹפְרִ ים. רוֹצֶ ה אָ דָ ם בְ קַ ב שֶ לוֹ A person prefers his own. And Hashem has nachas that we used our powerful Tzelem Elokim to be like Him and create a Yom Tov. The human was created to thank Hashem.
Dovid HaMelech said: מַה בֶצַע בְדָמִי בְרִ דְתִי אֶל שָחַת הֲיוֹדְ ךָ עָפָר הֲיַגִיד אֲמִתֶךָ תהלים ל י What good will be if I am silenced because of death; will I be able to thank You when I turn to dust? Will I be able to say your truth, that you are the Creator who created me and the whole world? As if the only problem with dying is not being able to thank Hashem! And this is the Mizmor (song) of Chanukah, which is the Yom Tov of Gadlus HaAdam. It is fitting that the Yom Tov created by humans should be total: יְ מֵ י הוֹדָ אָ ה thankfulness! And remember, if you aren’t thanking, then you are not a human. This is why mankind suffers so much (with wars, etc.). With all their kvetching, they aren’t being “themselves”!
And notice, while the Chashmonaim went to battle, they had banners stating: מַ כַ בִ י “Macabi”, which stands for: מִי כָמֹכָה בָאֵלִם ה' Who is mighty like You, Hashem; which is a praise for Hashem. Similarly, Yehoshafat Melech Yehuda didn’t go to battle; he just sang Shira and he won the war. And he was known for Gadlus HaAdam, since by him it says: וַיִגְבַהּ לִבוֹ בְדַרְ כֵי ה' דהי"ב יז ו he lifted his heart in the service of Hashem.
