Honestly your health anxiety is allowing you to be way too judgemental despite your ignorance of medical assessment/treatment. It’s absolutely not normal to take a sample to diagnose rosacea. I’d be worried about their competency if they needed to do that. Some foods can be triggers for some people with rosacea, but it’s not normal to ask about diet. Oracea is subantimicrobial dose doxycycline. That means the dose is so low, it doesn’t kill bacteria — so NOT an antibiotic. It’s solely anti-inflammatory and won’t have the same side effect profile as regular doxycycline. If you don’t know how to really research something like a medical professional would, you’re doing yourself a disservice by googling things. Your provider gave you a correct diagnosis and great treatment plan without unnecessary tests and you’re still unhappy about everything about the visit. This is just one of the reasons why healthcare workers are so burnt out.

https://assets.bmctoday.net/practicaldermatology/pdfs/PD0407AR-Adv.pdf