These days, I don't think it's particularly relevant. It seems like the mind-body problem is a stemlord's attempt to understand the relationship between objectivity and subjectivity. (I see the concept of qualia as a similar attempt). Physicalism is just an attempt at saying that since the mind ultimately stems from interaction with physical and chemical processes, we can develop scientific instruments to measure those processes, and if we can measure those processes, we can finally determine what a person's thinking and reproduce those subjective processes. In other words, we can crack open a person's subjectivity and bring it forth to the realm of objectivity. You see this a lot with stemlords who think that once neuroscience is sufficiently developed, we can basically clone people's personalities. This is their desire behind physicalism.

But an individual's subjectivity can never be breached. It will always be a black box. At a basic level, if you believe only the physical is real, how would you go about physically measuring the stew of chemicals in a person's body without have said measurements physically interfering with the interaction among the stew? It's like if there's an opaque container with volatile fluids of various colors interacting with one another. Cracking open the container to see what colors the volatile fluids are while inside the container is impossible because the act of cracking open the container itself means the volatile fluids are not longer inside a container but exposed to the outside world that would have unattended effects on the colors.

This means calling a person's subjectivity "the soul" or "idiosyncratic stew of chemicals" is mostly a semantic issue. I would use "soul" because it gets the message across and you don't sound like a cringey Reddit atheist.