Vegans needing to find alternatives for meat and dairy

I feel that a major issue with a vegan diet is that by avoiding meat and dairy you cut such a massive amount of foods from your diet. To avoid diary products you have to stop eating cheese, milk, butter, eggs and cream. To get round this there are vegan diary substitutes and fake meats. Do you feel a flaw with the vegan diet is that vegans claim they want to avoid diary and meat but create substitutes. If a plant based diet was a viable choice as vegans claim, should it not be necessary to create meat and dairy substitutes.