וַיֹּ֙אמֶר֙ ה’ אֱלֹקים לֹא־ט֛וֹב הֱי֥וֹת הָֽאָדָ֖ם לְבַדּ֑וֹ אֶֽעֱשֶׂה־לּ֥וֹ עֵ֖זֶר כְּנֶגְדּֽוֹ
Hashem Elokim said: It is not good for the man to be alone; I shall make for him a helper opposite him.
– Bereishis 2:18וַיֹּ֛אמֶר חֹתֵ֥ן מֹשֶׁ֖ה אֵלָ֑יו לֹא־טוֹב֙ הַדָּבָ֔ר אֲשֶׁ֥ר אַתָּ֖ה עֹשֶֽׂה׃ נָבֹ֣ל תִּבֹּ֔ל גַּם־אַתָּ֕ה גַּם־הָעָ֥ם הַזֶּ֖ה אֲשֶׁ֣ר עִמָּ֑ךְ כִּֽי־כָבֵ֤ד מִמְּךָ֙ הַדָּבָ֔ר לֹא־תוּכַ֥ל עֲשֹׂ֖הוּ לְבַדֶּֽךָ׃
Moshe’s father-in-law said to him: This thing which you are doing is not good. You and this nation that is with you will languish, because this thing is harder than you[r abilities], you can not do it alone.
Only twice does the chumash refer to something as “לֹא־טוֹב — it is not good”. The first is an assessment by Hashem at the creation of humanity, “seeing” (really: letting us see) that Adam needs a wife. The other in this week’s parashah (Yisro), when Yisro sees Moshe trying to single-handedly teach Torah and decide halakhah, and suggests that Moshe deputizes a hierarchy of what we would eventually call rabbis to handle the easier questions. And both times, it’s “לְבַדּ֑וֹ / לְבַדֶּֽךָ” alone.
A person is supposed to be connected into a society. Trying to make it לבד, alone, is the very essence of what is means to be “not good”; it is something other than what Hashem made us and the world for.