The idea that the rates of disease increase when screening increases is widely known. Any epidemiologist who tries and analyze data and model disease trends accounts for a number of factors that can impact prevalence - screening rate, screening accuracy, etc.
The number of people with a disease can stay static, but the number of diagnoses can increase dramatically with widespread screening and accurate tests.
Moreover it’s a vicious (virtuous) cycle. To get better funding to research a specific disease experts will play up how important their research is by playing up the severity, the “increasingness” of the thing.
With funding secure you can now roll out more research studies that tell practitioners all about the disease and how it’s “increasingly important”. Now doctors will test more patients for the disease, maybe over diagnose it too. And so and so forth.
Humans are flawed. Humans make research. We should be more skeptical about supposedly “established” science.
The number of people with a disease can stay static, but the number of diagnoses can increase dramatically with widespread screening and accurate tests.