What is an important reason that dsm-5 has replaced the broad diagnostic category of "dementia" with the term "major neurocognitive disorder"?

According to the INESSS report in Quebec, the term dementia has been

replaced by 2 pathologies depending on the severity, to improve the classification of the dementias:

Mild neurocognitive disorders (TCL, MCI) and Alzheimer's disease and other major neurocognitive disorders (TNCM).

The term major neurocognitive disorder, (which replaced dementia in DSM-5), is characterized by a cognitive decline from previous performance level in one or more cognitive domains (complex attention, executive functions, learning and memory, language, perception-motor skills, social cognition) that interferes with independence in daily activities (diagnostic criteria).

The DSM-5 also defines a mild neurocognitive disorder that corresponds to what is commonly known as mild cognitive impairment.