I don't understand your question at all! That verse, 5:21 is Benei Yisrael complaining to Moshe and telling him to stop bothering them with what he has done so far to try to free them, and that they are happy to serve Pharaoh, but not put their lives in jeopardy:
וַיֹּאמְר֣וּ אֲלֵהֶ֔ם יֵ֧רֶא י״י֛ עֲלֵיכֶ֖ם וְיִשְׁפֹּ֑ט אֲשֶׁ֧ר הִבְאַשְׁתֶּ֣ם אֶת־רֵיחֵ֗נוּ בְּעֵינֵ֤י פַרְעֹה֙ וּבְעֵינֵ֣י עֲבָדָ֔יו לָֽתֶת־חֶ֥רֶב בְּיָדָ֖ם לְהׇרְגֵֽנוּ׃
and they said to them, “May Hashem look at you, and judge, because you have made us a stench to be abhorred in the eyes of Pharaoh, and in the eyes of his servants, to put a sword in their hand to kill us.” (Alhatorah translation)
This is exactly what they are saying here, except that now that they are out in the desert, they add a line about dying in the desert:
הֲלֹא־זֶ֣ה הַדָּבָ֗ר אֲשֶׁר֩ דִּבַּ֨רְנוּ אֵלֶ֤יךָ בְמִצְרַ֙יִם֙ לֵאמֹ֔ר חֲדַ֥ל מִמֶּ֖נּוּ וְנַֽעַבְדָ֣ה אֶת־מִצְרָ֑יִם כִּ֣י ט֥וֹב לָ֙נוּ֙ עֲבֹ֣ד אֶת־מִצְרַ֔יִם מִמֻּתֵ֖נוּ בַּמִּדְבָּֽר׃
Isn’t this the word that we spoke to you in Egypt, saying, ‘Leave us alone, that we may serve the Egyptians?’ For it were better for us to serve the Egyptians, than that we should die in the wilderness.” (Alhatorah translation)
