I am not going to speak about any of the other things you've mentioned. Flat earth, well...I don't feel it's even useful to get into it. To be honest, even, if we were all wrong, and earth was in fact flat, it doesn't really matter. We're not going to be different people because of it.
But one thing I would like to discuss is the part where you mentioned that before the internet, we'd go to a doctor with an ailment and get diagnosed, or by another if he/she didn't know. Yes, doctors have studies medicine in school, and therefore we expect them to do their jobs right. But what most seem to forget is that not one doctor is proficient in everything, and sometimes they should listen to people outside of their profession.
I will give you an example. My 17 year old daughter felt sick, when I brought her to the GP, I looked at her, and because I know the symptoms, I called it: gall stones. I mentioned this to the GP, who gave me the 'oh you self-diagnosing Google doctor' look and completely ignored it.
Two days later, we landed in the A&E, I mentioned the same and got the same treatment. She ended up spending 5 days in the hospital, getting prodded and stuck with needles, and no answers. Because she didn't eat (she couldn't, because she threw up everything) and because she had lost weight, and also because she is a teenager, they were barking up the wrong tree. In their mind, she had a eating disorder and they were going to find out and prove this. The fact that I told them that I knew what she eats in a day, and that an eating disorder wasn't even possible, because I know my daughter, didn't seem to matter.
They never even looked at the possibility of gall stones, because it's not very common in people her age. However, they forgot that not only eating habits, but also stress can cause these nasty stones.
Anyway, after five days of prodding and needling her, and a LOT of pain for her, because they didn't treat her, only prodded, they finally came to a conclusion: gall stones...
All this prodding could have been prevented if they would have listened to me and looked for what was obvious to me (her skin was yellow ffs!)

Yeah, I'm not a doctor, and I am not under the illusion that I can identify every illness. However, I am not a car mechanic either, but when my car makes a certain sound, I can identify exactly what it is and tell the mechanic about this. And guess what? 9 out of 10 times the mechanic will look for this first, before he goes on to search for anything else. The problem with doctors, and people who put their lives in their hands completely, is that they think these people are gods and know all. They don't. They're human. My own mother was one of those trusting people, and it was a doctor who killed her.

So while we shouldn't trust doctor Google completely either, it sure helps to find those things the doctors don't.