Sysdig report finds 310 percent growth in container density since 2018. 58 percent of containers are running as root, but this is a small portion of total containers. Docker represented 99% of containers in use at that time in 2017, down from 79% in October 2019. The median number of containers-per-host more than doubled from 15 in 2018 to 41 today, indicating a growth in efficiency and a shift in cost savings as containers mature. The short life of containers reaffirms the need for container-specific tools for security and monitoring.
Source: https://www.helpnetsecurity.com/2021/01/14/containers-runtime-security-risk/