Side benefit: also factory farms can totally be a source of another fucked up disease. They pump those animals with antibiotics and put them in bad environments a lot of the time.
* Commercial, at-scale plantations kill a huge number of insects, and animals, like rodents and field mice by pesticide use and by machinery during harvests.
* Commercial farming pollutes the rivers and water table, because of the run offs of pesticides. Which makes animals sick (people are a subset of animals here).
On the other hand, meat production does not need to be harmful at all, and in fact, can have the opposite effect of healing the land.
Look at Joel Salatin's farms. He is the model for proper meat production and has been featured in countless docs and books. His farms are fully integrated with nature. Yes the product costs more, but that is a feature, not a bug. The product is of much higher quality, and you need less of it to get the same benefits as you would from factory-farming raised meat. Because it is more expensive people will naturally eat less of it, which is ok and is also a feature.
The problem is that American government was subsidizing terrible farming practices for a very long time and all food became too cheap. Everything is raised and produced with shortcuts and external costs that are not accounted for. That is the root cause of all issues.
Switching from meat to soy will not fix the problem, because soy is and will be subsidized even more, if there is more demand for it. The soy industry will get stronger and lobby for more subsidies and they'll get them, like they get them for everything else.
And yes, factory farms need to go! It is way too centralized and is actually a danger to society in many ways. Farms need to be decentralized and operated by a higher number of smaller operators. The economy of farming will be healthier and more diverse overall.
Edit: Failed to mention that a lot of deforestation is done to facilitate the growth of soy. Take for example the Amazon.
[1] can be biased: https://impossiblefoods.com/mission/lca-update-2019/