If one of your reasons for being vegan/vegetarian is because of the harm the animal products industry does to the planet, I think being concerned about all the artificial and synthesized chemicals in the food ingredients, how the grain is grown and how the factories dump their waste. There is likely much more harm from, for example the byproducts from grain production alone in the Frosted Mini-Wheats, than the gelatin (more grain than gelatin in the mini-wheats)). I would like to post a link specifically talking about that, but this link seems good. https://byjus.com/chemistry/soil-pollution/
If you pile up all the pollution going into the production: toxic ingredients, toxic wastes from pre, during and post- production and where they end up, I think that dramatically out weighs the admittedly high costs caused by industrial farming. By supporting local grassfed beef farms, for example, you are supporting sustainable farming and getting a happy cow. Yes, it is still interesting (among many words to say) to eat a happy animal/pet. That comes from being so far removed from the process, often for generations. Most people cannot subsist long term on a vegan diet (much more than B12). Short term can be good especially for someone to learn how many animal products there are. Meat reduction is certainly beneficial for most Americans.
My diet usually consists of organic veggies and fruits (ideally from local farms: higher quality and less pollution) and some (not 8oz 2 times a day) grass-fed meat (maybe 8oz a few times a week, or less than 8oz per meal.) What other ingredients are in the meal make a difference too. Also, grow your own food! There is so much good from growing your own food, including self-reliance, being more sustainable, less plastic, more community (if you invite it, gardeners are easy to talk with) and healthier food.
IMO choosing organic is a much bigger (and better) choice than vegan (if I were choosing based on pollution/earth effects). Check the owner though. Cascadian farms is owned by The smaller organic companies and farms pollute less. Especially, local ones where you can go to the farm.
Interesting links I found when looking for the organic brands bought by General Mills etc. (like Cascadian Farms). I would say they are much better than mainstream conventional foods, a quick look at the ingredients will confirm the lack of artificial ingredients etc., but not as high quality as our great-great-grandparents ate...
Brands that Don't Want GMOs Labeled
10 Companies Control Most or All of the Food You Buy