The culture is kept alive by people who have it. If they will not practice it anymore and will prefer to follow other cultures then they can come to lose their original culture. That is why there are many people who have the mission to preserve the culture that they had. They make efforts to record it, teach it to the young people, write it and any other things. They say it what makes them known and unique so it must be preserved. But not all are realistic.
That is because there are certain practices that are not suitable at this present time. With the changes that are happening across the globe, there are also practices that do not make sense already. That is because there is also an education that was received that let people know of things they do not know before that makes what they had believed as the true ad it must be done. That is why, at this time, culture is also evolving and changing to adapt.
There is also the culture that is just part of the practice in today to day life and it would not be changed as long as those who had it practice it. That is why if you enter the house of other people having a different culture, observe or inquire what is the culture they practice so you also could do it as a sign of respect. It is best to be prepared so as not to be embarrassed.