If you read the reports from the camps you see that there is a very high death rate. For example this woman (https://www.apnews.com/61cdf7f5dfc34575aa643523b3c6b3fe) claims that 9 of the 60 women in her cell died over the course of three months. Extrapolate that over 2000000 people being held and it's clear that this is genocide.