I think a lot of people in grad school go through something similar. Sometimes you get the imposter syndrome, and sometimes you get the sense that a lot of other people are imposters.

I cringe every time I hear someone in a professional setting say something like "we all have no clue what we are doing". Speak for yourself, lol, some of us know exactly what we are doing, and can tell you don't.

I guess the biggest piece of advice I can give is to just try your best to have a level confidence that matches your actual knowledge on a topic. Don't rely on your own expertise too much at this stage; if you think AI self-diagnosis is bad, find some research on it, and let that do any talking. Your biggest asset at this stage is scientific literacy, so use that.

MD's have all gone through the same experience, so they know what it's like. The thing that makes it a little harder in your field is that the very nature of being a medical doctor requires you to show confidence to your patients, and whether or not you are sure about something, you still have to make a decision to act (or not act). If a microbiologist doesn't have data to support their hypothesis, they can just say they dont have an answer and leave it at that.