Why is FRACTRAN turing complete?
I've tried to google for explanation but most links only say things like "FRACTRAN is turing complete. As an example, let's look at multiplication." I remember seeing an xkcd forum post say that FRACTRAN helped the poster understand Turing Completeness. I am looking for an intuitive explanation as to why this esolang is Turing complete, as it's not very obvious looking at the language mechanics.

I've tried to google for explanation but most links only say things like "FRACTRAN is turing complete. As an example, let's look at multiplication."
I remember seeing an xkcd forum post say that FRACTRAN helped the poster understand Turing Completeness. I am looking for an intuitive explanation as to why this esolang is Turing complete, as it's not very obvious looking at the language mechanics.