There is some thought that meat eating is not going to go away, and that provided animals are humanely reared and properly looked after, that ruminants should be increased in number. They recondition the soil which is already depleted in minerals by poor agriculture practice, and are suited to the large areas of UK not suitable for arable/veg production.
As long as they are pastured, not in huge feeding stations fed rubbish and soy, they will provide omega 3 fats, minerals, vitamins, and other essential nutrients. eg vit B12, and lutein.
These are necessary for good health.
As for being vegan, I quite understand the moral purpose, and there are some lovely recipes for beans and veg, many from the East. However, there is a need to not go for the cereals as carbs are sugars, and too much sugar can give rise to diabetes 2.
Personally I don't see why there is a need for pretend meat. This is just a marketing opportunity to make money out of the climate emergency, pushed by powerful investors and hedge funds. There are delicious vegan foods without the use of hydrolysed pea protein and chemicals we cant pronounce the names of. IMO.