Phenomenon 5, commonly referred to as "Environment Restoration", is a force thought to be responsible for the lack of decay in the Backrooms.
Description:
Phenomenon 5 is an anomalous force that is present on the majority of levels in varying intensity. This is evident by the fact that some levels are covered in mold and decay while others are unnaturally clean. This effect is most prevalent on levels such as Level 5 and The Whiteout, where any unclean spots made will quickly disappear in minutes. The cause of this phenomenon is unknown, as most research operations conducted by the M.E.G. have been inconclusive.
This effect is usually present at some degree on most levels, such as Level 0, which does not seem to deteriorate or show further signs of age. Additionally, it was discovered that any form of waste produced by humans or any other animals typically gets reverted quickly, showing no signs of ever being there.
Furthermore, this phenomenon can also explain countless oddities of the backrooms, such as the constant "spawning" of crates in levels such as Level 3, and the refilling of vending machines and coolers in various levels. It may also explain why electricity and other things requiring human involvement continue to function despite none of these things being present.
Discovery:
The idea of Phenomenon 5's existence was first brought up to question after the discovery of Level 5. Other levels which include a high intensity of this phenomenon are The Whiteout and Level -33.1.