Most of the major causes of global hunger - poverty/prices, food shortages, food wastage, drought/famine/climate change, lack of diversity in available foods - would be alleviated if not outright solved if global food production were increased 10 or 30 or 50% by growing crops to feed people instead of cows. Roughly one in nine or ~11% of the world population are under-nourished, and the figures used in the OP assume only a third of the deaths from hunger can be attributed to meat consumption; that is, my numbers suggest that increasing potential global food production by 50+% would solve the hunger issue for less than 4% of the world's population. If anything, that seems like a ridiculous understatement!
A direct comparison for your argument would be that the solution to Covid isn't wearing masks or getting vaccinated; we could solve the problem through a weeklong national lockdown followed by mandatory daily testing of all people and forced quarantining in government facilities of those who test positive and their associates. That would be a national solution, but it's obviously not the simplest and certainly not the lowest-impact way of addressing it.
Similarly, in theory global hunger could be solved without changing current dietary habits in wealthy countries* by changing many other different variables (ie. ending wastage associated with market-based distribution of food, eliminating global poverty, improving agricultural, storage and transportation technology and infrastructure in underdeveloped countries...), and indeed many of those are things which should be done, but the far more obvious and simpler first step is to stop wasting food through inefficient production and consumption habits. *And of course, even if all those things were done we'd still need to change the trend of increasing meat consumption with increasing wealth, essentially telling the rest of the world that it's okay for Americans to chow down 150% of their bodyweight in meat each year but no-one else emerging from poverty can do the same or there won't be enough room on the planet for all the cows!