FALSE. Realizing one's true nature as Brahman doesn't mean abandoning action. The jivanmukta (liberated while living) acts in the world without ego-identification. Krishna teaches Arjuna in Gita: perform your duty (dharma) without attachment to results. Action continues; compulsive doing driven by ego-desire ceases. Most great Advaitic teachers (including Shankara) were extraordinarily active, establishing institutions and serving society.