I got visible abs and veiny as hell without those supplements and eating only 30 grams of fat per day.

High fat diet = sluggish mind and body.
The body needs carbs, high carb + low fat = the diet of every Olympic athlete. Show me one Olympic athlete that follows a low carb high fat diet.
High fat diet (over 60g per day) + high carbs = recipe for type 2 diabetes btw.