Real estate is one of the primary reasons that high density fiber enclosures are deployed in the data center. In some parts of the world, real estate is very expensive. One way to save cap ex is to try to use the smallest data center possible. The smaller the data center, the less square area required, and therefore, lower cap ex. This would certainly be the case if one is using a co-lo facility. Of course, a smaller data center also means lower op ex, e.g., less cooling, etc.
Another reason, also driven by real estate, is that the data center’s size is fixed. The data center cannot be enlarged. This might be the situation in dense urban areas where a larger space does not exist. The only way to add more functionality to the data center is to try and find a way to cram in more equipment. Hence, using a high density fiber enclosure.
Another less obvious reason for using a high density fiber enclosure is the trend towards data centers becoming profit centers. Historically, data centers were perceived as a cost of doing business. Depending on the business you are in, that may no longer be the case.