I suspect that most of them are under medical care because they followed the government’s high carb dietary recommendations (i.e., food pyramid), as their ‘doctors’ likely recommended they do.
Your first point is a fine distinction, most people here with success stories are not TELLING others what to do, but rather what they’ve had happen in their lives. They’ve had success, which even you appear to believe, yet NOT ONE PERSON HERE, not even yourself (based on your earlier posting), can match what they saw using a any type of high-carb diet, relatives to knocking down their blood sugar and meds.
We all get to choose who we trust, and I trust FReepers here MUCH MORE than the medical community on issues where literally NO ONE understands all the processes going on.
Bill Clinton went plant based after his bypass surgery, taking the advice of Forks over Knives’ Caldwell Esselstyn:
https://www.disabled-world.com/fitness/dr-caldwell-esselstyn.php
My, doesn’t he look healthy now?