EDIT (for below): Jokes, there's plenty instruments in this one, I was just totally awestruck and only focused on the voice and guitar :/
Modern movies saturate your attention visually and often struggle to do much else. Whether that's because of volume, plot familiarity, or an over reliance on technology to entertain, it helps prove the point I'm trying to make here.
It's just her voice and a guitar, and if you're pedantic, some percussive fills for added atmosphere. The allure here is similar to why I'm drawn to black and white films. Using less devices means more time is spent focusing on the substance, here I'd say it's most noticeable melodically. I wouldn't say the song's elements are simple, but in terms of the sounds you're only really hearing two things, a voice and a guitar.
"The Bug Collector" is part of an album I'm about halfway through, and if I make it the whole way it might be the first folk album I've finished this year. After having previously only dipped a toe, I'd say both feet are in the water on this artist.