A large percentage of people want their doctor to prescribe them antibiotics when they have a virus. It’s been shown that doctors who over-prescribe antibiotics get better patient reviews for example.
Now you have a “better UX” that pops up that gives people exactly what they want. They answer a few questions on a website and they get an antibiotic prescription.
There is no way for the medical establishment to compete with a site that will give people what they want even when it’s harmful to them without even requiring any kind of examination.
In the case of antibiotics, this kind of behavior breeds resistant bacteria that regularly kill people.
In the case of other drugs or combinations of drugs, the risks are usually only to the patient themselves. But the risks are real and patients assume this stuff is regulated.