Based on Martin's Dunk & Egg novellas, this story has no dragons, no magic, and no zipping back-and-forth across Westeros. It sounded like the perfect solution to two of the streaming industry's largest problems: 1/ Every entertainment company wants universes of IP until they realize that scale does not easily translate into TV, and 2/ No showrunner can predict how much they can or cannot deviate from the source material and still hold their fanbase intact.
The first "Toxic Avenger" film, a Troma classic directed by the inimitable Lloyd Kaufman, arrived in theaters in 1984, eventually spawning three sequels, a stage musical, a Marvel comic book series, a video game, and an animated television series. Not too shabby! Of course, with legs like that, reboot talk couldn't be too far off. And reboot talk did indeed happen, in 2010, in 2013, and in 2016.