Noach, just like the rest of us, wasn't perfect, but he stood out from his neighbors because he did the best he could to follow Gd's will. Noach was different from everyone else, and so were his descendents.
9These are the generations of Noah, Noah was a righteous man he was perfect in his generations; Noah walked with God. טאֵ֚לֶּה תּֽוֹלְדֹ֣ת נֹ֔חַ נֹ֗חַ אִ֥ישׁ צַדִּ֛יק תָּמִ֥ים הָיָ֖ה בְּדֹֽרֹתָ֑יו אֶת־הָֽאֱלֹהִ֖ים הִתְהַלֶּךְ־נֹֽחַ:
Unlike in the stories of Abraham and Yona, Noach didn't argue with Gd, and Gd didn't instruct Noach to warn the other people, ask them to repent. This is a very serious difference. Even though many years/centuries had passed since Gd created man, Noach was still in the earlier generations, and maybe there was a genetic difference in Noach from the others of his generation.
While the others were more connected and socially/emotionally dependent on each other, Noach was a loner, maybe even a bit "autistic" socially inept or oblivious to what was going on. That is what kept him away, made him immune from the perversions of society.
Noach wasn't what's called in Hebrew ראש גדול Rosh Gadol, Big Head or one who sees steps ahead and takes the initiative.
What Gd commanded, Noach did. No questions asked. Being "Socially Inept" is a safety valve. It saved Noach and his family. He was attuned to Gd and not to society.
22And Noah did; according to all that God had commanded him, so he did. כבוַיַּ֖עַשׂ נֹ֑חַ כְּ֠כֹ֠ל אֲשֶׁ֨ר צִוָּ֥ה אֹת֛וֹ אֱלֹהִ֖ים כֵּ֥ן עָשָֽׂה:
At present the State of Israel and the Jewish People can use some of that "ineptness," lack of focus on what the world wants. We should just be focused on what Gd is commanding us, because our Salvation will only come from Gd Almighty and not from the nations of the world and their perverse values.