Based on not having a realistic choice. The only person I personally know to successfully pull it off is an acquaintance that's rich by local standards, doesn't work, spends a lot of time sourcing and cooking it, and also eating it. He needs to eat more for same energy. It's so involved that most of his life revolves around it. It takes a good bit out of his time. The rest of the people from that friend group couldn't afford it, couldn't afford spending the money, couldn't afford spending the extra time on it.
I personally wouldn't eat meat if I had a good alternative. I rarely do, I eat it for health related reasons, considering my setup.
Yes, and if you have such a care-free attitude towards a vegan diet you should expect to become deficient in all sorts of necessary nutrients.
Everyone who treats plant-based diets with any degree of responsibility will stress the need to plan them carefully, considering the needs of the individual and their stage of life, and to accompany them with supplements to make up for the nutrients that not even well-planned diets cannot provide.
For example, "Top Tips" from the British Dietary Association:
* Carefully planned plant-based diets can support healthy living at every age and life stage
* Plant-based diets can help to manage weight and may reduce the risk of type 2 diabetes and other chronic diseases
* You can get all essential nutrients from plant foods but vegans need to ensure a reliable source of vitamin B12
* If excluding dairy, make sure you consume other calcium-rich foods
* Include a wide variety of plant-derived foods to ensure your diet is balanced and sustainable
I personally wouldn't eat meat if I had a good alternative. I rarely do, I eat it for health related reasons, considering my setup.