Why is this working, let me list out some points
1) Its all about how 2 different people with different family back grounds and entirely contrast dreams are becoming one supporting each other with mutual trust and bond. And their very matured, old fashioned innocent love. I agree with you, there is no much romance shomance but the moments between them are so magical, realistic and mesmerizing. They are slowly building their relation; The way they understand each other, the way they assure each other without much talking is just unique.
2) I agree previously there used to be more Bhabhos drama but after knowing the truth, these 2 Sandhya and Bhabho share a special relation, Bhabho is changing now; I still believe there are so many people like Bhabho in India, hope they too change with time. Though Bhabho shouts all the time, actually she is very good natured one. She loves the family and she works hard for the family. And her dialogues are very unique and most of the times hilarious.
3) Coming to Meena, she is the best comedian I can say, people love her acting. I can't say she is a villain because most of the times she will be doing silly things. She is just insecured, lazy , money lover. In spite of these bad habits, she wants to be in Bhabho's good looks all the time, she wants to survive in the house without spending money, that's why she will be ending up with little scheming & more lies. So overall there are no negative characters in DABH.
4) All the other characters Chotu, chaturi, Bhabhasa are real entertainers and are so innocent.
5) We all know the outcome of the story: an uneducated husband supporting his wife to become IPS officer but still there are so many twists and turns, every track is so interesting and surprising, closing all the loose ends at right time.
6) Everyone's dialogues are so well written. All the actors are so perfect for the roles, Deepika is not dumb, she improved a lot these days, Confession scenes and all the scenes after this proves Deepika is the perfect one for Sandhya's role. And coming to Anasji I can say he is more than perfect. All the scenes especially when he found divorce papers, all the cooking scenes prove that no one other than him can fit into the role.
7) So many social messages from DABH most of the times, strength of the leads and the way they respect elders……….
List is endless….. Everything is so special & unique; we have good story & dialogues, suspense, drama, comedy, love, dreams, social messages, encouraging words, innocent relationships …..Attracting so many people like me who never ever watched any shows before. It's something magical and addicting.