"Wellness" is not just alternative medicine, it is essentially a theory of the body which posits if something makes you feel better, you are better in some meaningful way. I would argue it one of the most commonly held nonreligious magical beliefs in the modern world.
Wellness as a concept has its genesis in the 1950s with "workplace wellness" programs, a sort of budget alternative to offering employee healthcare benefits. This was an era soaked in itinerant business preachers offering classes on things like "hypnosis at a management level" and "yoga to improve leadership abilities". I am exaggerating for effect, but not by much.
The capitalist medical system regularly abandons people. We've all heard stories of profit driven pharmaceudical companies holding the ill hostage for extreme markup on life-saving medicines. People have real, legitimate, reasons to mistrust medical professionals.
Let's say you have chronic pain, and everything your doctor offers you is either ineffective, expensive, or addictive. You are desperate for literally any release, so you start looking into other solutions. You will find an OCEAN of snake-oil salesmen willing to sell you "the secrets doctors don't want you to know."
What is frustrating, is that pain is actually partially psychological. Some wellness techniques may have an actual, medical, benefit on some patients. The worst thing a conspiracy theorist can have is a point. So now you actually do kinda feel better, and you have a sense of loyalty to the grifter selling you 300$ Sumerian Cock Oil Pills. These people are the core of the wellness industry. They are the examples that everyone else points to and says "Well it worked for them!"
Reactionary thought blooms in environments like this. If the medical industry can't be trusted, what else can't be trusted? At any given time, you are two clicks away from "vaccines cause autism." Three clicks away from "Cavemen were 15 feet tall because they only ate meat." And four clicks away from "The medical industry is controlled by The Jews to drain our wallets and keep us sick." Echoes of Nazi attitudes towards German-Jewish doctors are a common backbeat.
Wellness itself is relatively harmless, (compared to the things it is adjacent to) but it acts as a sort of idealogical airport that exposes the curious to a deluge of potentially radicalizing communities. The longer you spend in communities like this, the higher the chance you'll come across something that meshes perfectly with your own biases.