They may have been Chained there at one time. Not now.
Satan's demons also roam the earth too.
Criminal Fallen angels, aka demons, with bodies are chained in Tartarus. Fallen angels without bodies still roam.
Lucifer upon his fall was known as Satan (HaSatan).
He has 3 falls recorded in Scripture. The fall to Earth, the fall in the Garden, and the fall into the Lake of Fire. Each was a situation of perfect environment. So, if anybody seeks perfect environment as a solution for sin, they have 3 cases overturning that hypothesis.