It's really really tough to achieve or maintain 0 carbs in a day's food intake. This is one of the reasons why you'll not come across many who have done it.

On a keto diet, one can attain < 20g carbs per day with some struggle but to cut it out entirely is really hard without missing some other essential nutrients - because at least some carbs tag along with other things.

It's not really. Most traditional religions have fasting practices and pretty much all our ancestors did it from time to time. A 7 day fast here and there is completely natural and not that hard after the first 30-50 hours.

Your point is irrelevant - the post you replied to asserted that it's tough to create a diet with no carbs, to which your suggestion is to not eat at all. Not eating is not a sustainable diet.

It is a sure-fire way to get into keto if that's your goal. Also there are some significant advantages to intermittent fasting vs continuous calorie restriction: https://www.dietdoctor.com/intermittent-fasting-vs-caloric-r...

You're right. But even in terms of unrefined carbs like certain sugary fruits I couldn't have without it affecting my blood sugar levels.