There was a prompt earlier where soulmates swap bodies at some point and have to find one another in order to swap back. It's a great idea but it gave me another idea.

At some point during their lives, two soulmates who have met and know each other well, swap bodies permanently. After all, soulmates are essentially two halves of the same person, the body they are in is immaterial. It doesn't happen to everyone, and nobody knows what triggers it, but nobody has ever swapped twice.

Matt and Foggy are soulmates (platonic or otherwise) and Matt lives in fear that it will happen to them, he doesn't want Foggy to have to experience the world as he does, plus it would mean hanging up the Daredevil suit for good. He tries to distance himself from Foggy in the hopes that that will prevent the switch. Foggy, on the other hand, almost wants it to happen. He finds the idea a little scary, but he thinks it will save Matt. He starts to live healthier so his body will be healthy for Matt if he ever inhabits it, and learns Braille and cane technique etc in case he needs it.

Maybe they do switch, maybe they don't, author's choice.