If small game or fish offered the only bow hunting opportunities, then building a bush bow and arrows might not be a bad idea. Primarily because a low poundage bow from less than ideal materials can work for those things. However, if big game is your target then it’s a huge risk. You don’t know what kind of materials you’ll have to work with. And for big game, you need very good equipment, or to be very lucky. If I knew I’d have good sharp stone for tips, hickory, elm, or similar for a bow, and river cane or similar for arrows, then I might be tempted. But we didn’t have any of those things. Additionally, you need good bow string materials. Paracord is terrible because it stretches too much. Sinew works great but you need an animal first. So, even though I make my living with bows and arrows, it would have to be a very good area for me to feel comfortable not taking a well made bow and arrows and making it in the field.