Here what I think : Trent was a huge fan of Bowie.
Bowie used to change his style every new release/album and Trent got the inspiration from that
Nine Inch Nails is an anthology like the tv show american story or Black Mirror : every season/episode is different but with some constants (in the case of NIN : trent's voice (except for ghosts) and a moog)
For TDS, Trent had that "industrial" vibe with the machines (Reptile). Now, every other bands with dark and machines sounds is defined as "industrial"
But was Trent the first one ever to invented the "genre" ? I cannot find things like this before him. You can quote ministry or skinny puppy but they did not have that "machines" "cogwheels" sounds in it.
Here is another example of a really cool song with dark industrial machines by example : https://open.spotify.com/track/739I7bqUbxDu7vkjz1k8iE?si=WnjGBxwrRZCrrA44JChdyA