Arguments that meat take an excessive amount of resources are disingenuous because those resources cannot simply be translated to other uses, examples being that the water use example many tout uses rainwater would fall anyways, that livestock will eventually urinate meaning it isn't actually lost, and land used for livestock is mostly non arable land and therefore cant be used for producing crops anyways. Also there is a relationship between livestock, agriculture and human society where they all are able to use resources that each other cant, or provide benefit to each other. For example a huge amount of agriculture fertilizer comes from manure, and a huge amount of livestock feed comes from agricultural waste. Without livestock we now have to get fertilizer elsewhere, and all the byproducts that would become animal feed becomes waste.
In the grand scheme of things livestock produce an insignificant amount of ghg and that if all Americans stopped consuming beef, it would reduce the nations ghg emissions by ~2.5%, whereas transportation, power generation and construction contribute to the overwhelming amount of emissions (~80%).
If you want to look at reducing emissions from food, it is much easier to look at food waste, where ~40% of food in the US is wasted, and of that roughly 80% is produce like fruits, vegetables, tubers etc, meaning that even if there was a transformation to a purely vegan population, food waste would probably increase.
edit: I should reiterate that these are points in summary that are made in the video, not my personal opinion.