In my opinion, when a child is already surrounded by a larger number of adults from an early age, whose view of life is radically different, this can only play into the hands of the child, because it will help him grow a more versatile personality and he will have a more developed worldview. In addition, this can serve as an openness of the child in the future, that is, having already got used to a large number of people around him from an early age, he will become more sociable and will not be afraid of crowds of people.
Having grandparents and other relatives who are involved in the upbringing of a child can help parents feel more free and also devote time to themselves and their career. Given that sometimes the prices for basic things for newborn children are prohibitively expensive, the salaries of one family member (usually the father, since mothers cannot work immediately after childbirth) may not always be enough, and parents have to cut their spending. Here other relatives can come to the rescue: they can, for example, sit with the child, thus allowing the mother to go to work.
As for the disadvantages, I can't imagine any, because, in my opinion, this is a very good concept of perception.
In conclusion, I would like to say that the idea of a close-knit family has many advantages for all family members, and that it undoubtedly needs to be promoted.