What is Advaita-vaad in a very practical sense?
It is the ability to know that which is common in all things.
A gold-maker does not see bangles, or necklaces or ear-rings. He sees only gold. He will look at them and say 2-bhori, 1-bhori and 3-bhori on inspection. He has developed through training the ability find out the essence, which is gold in his field.
Similarly a doctor is able to find out the root cause of a disease from symptoms. And so on.
Better still are those people who can abstract out the essence from multiple domains of knowledge, and re-use and re-contextualize that knowledge in a different field.
Extracting the essence is the path of Advaita-vaad. There is a difference between knowing something and becoming one with the knowledge. Advaita teaches us how to relate to knowledge, rather than simply knowing.
This can be achieved through bhakti, karma and gyana margas simultaneously. Through repetition and sadhana, over time one develops the ability to visualize the essence of multiple non-related domains.
Over time, he reaches a state where he sees only the essence, and the entire world as a myriad projection of that essence. This imperishable reality is what is known as Brahman.
Developing this ability to extract the essence of any domain is immensely practical as we negotiate our way in this highly competitive world.
Advaita-vaad as a knowledge system is in a sense like artificial neural networks. A lot of sadhana or training is required. Lot of iterations. A model is generated, but it is like a black box. Noone understand why it works. Bhakti, karma and gyana work together seamlessly, but there is no simple causation.
But a well-trained neural net can produce wonderful real-world output. Similarly a person trained in the way of Advaita-vaad is supremely practical without getting bogged down by the trappings of "modernity".
While moksha or becoming Self-realized is the end-game, and that too for a small minority, for ordinary people like us, it is the journey of Advaita itself that can bring about a sea-change in our perspectives,personalities and approach to life. A change for the better.