Medical science is just that, medicine that follows the scientific method. (Or at least it's supposed to).

The scientific method is basically testing guesses (sometimes educated ones) and seeing what happens.

There's a whole lot of structure and guidelines, but testing guesses(hypotheses) is where it's at mostly.

The current state of any science is usually "the best theory we have right now, given the data and resources available to us"

Some people hear that and think "look, they're just guessing, why should I listen to them?" and thats absolutely valid.

Where that falls down is that they then go on to assume all guesses are equal and ignore the time and resources that went in to that current scientific best guess.

Is it always correct? no, is it more likely to be beneficial than a random social media post by an influencer with no medical expertise? Generally yes.

sort of trying shit and then are happy it worked

Most professions could be described like this, but when doctors are "trying shit" it is backed up by many years of training and education, and their behavior is scrutinised by professional bodies and so on.

When your local quack is "trying shit" it's just based on the vibe.

"Herbal medicine's been around for thousands of years!" Indeed it has, and then we tested it all, and the stuff that worked became 'medicine'. And the rest of it is just a nice bowl of soup and some potpourri.

From Dara Ó Briain. Also from him:

Chinese medicine, oh, Chinese medicine! "But there are billions of Chinese, Chinese medicine must be working." Here's the skinny on Chinese medicine. A hundred years ago the average life expectancy in China was 30. The life expectancy in China at the moment is 73. And it's not feckin' tiger penis that turned it around for the Chinese. Didn't do much for the tiger, if you don't mind me pointing out.

It's a private company in the "health and wellness" industry. Basically modern day snake oil salesmen that convince vulnerable (or stupid) people that "big pharma" is evil and giving you cancer or whatever, while the mystery pill they're peddling will cure anything that ails you. It typically comes with a hefty price tag, lots of sales pressure, and zero evidence to back it up.

Yeah this is kind of an US insider post.

Edit: I'm having a bad day so I am elaborating: oftentimes they reeeeeally don't consider there's literally a world out there and the internet is connected to that world and some information can be totally confusing because it's so US centric.

Native speakers also confuse this and end up in the backs of ambulances.

It's purposefully worded that way to be misleading, even to native speakers. Explicitly calling something medicine or a cure means it would have to be tested and regulated. However, labeling something as being for wellness isn't covered by that, and is just vague enough to have people think positively about it. That's not saying that there aren't beneficial things labeled under wellness; roughly speaking though, it's can be used to sell whatever you want, while making people assume it's actively good for them.