Another interpretation: things used for a stricter holiness may be used for a lighter holiness. What does "he shall put on" teach? To include the worn-out garments. And Rabbi Dosa follows his own reasoning, as it was taught: "and he shall leave them there" (Leviticus 16:23) - this teaches that they require storing away. Rabbi Dosa says: only that he may not use them again on another Day of Atonement [but they may serve an ordinary priest].
Yalkut Shimoni on Torah 483:2
Yalkut Shimoni on Torah 483:2
דָּבָר אַחֵר דְּבָרִים שֶׁנִּשְׁתַּמֵּשׁ בָּהֶן קְדֻשָּׁה חֲמוּרָה יִשְׁתַּמֵּשׁ בָּהֶם קְדֻשָּׁה קַלָּה. מַה תַּלְמוּד לוֹמַר "יִלְבַּשׁ" לְרַבּוֹת אֶת הַשְּׁחָקִים. וְאַזְדָא רַבִּי דּוֹסָא לְטַעְמיֵהּ, דְּתַנְיָא (ויקרא לז, כג) "וְהִנִּיחָם שָׁם", מְלַמֵּד שֶׁטְּעוּנִין גְּנִיזָה. רַבִּי דּוֹסָא אוֹמֵר שֶׁלֹּא יִשְׁתַּמֵּשׁ בָּהֶן בְּיוֹם הַכִּפּוּרִים אַחֵר.