“Modern” is not always better than old. “Modern” can be very fragile in addition to being high-maintenance, expensive, and bad for people & ecosystems. Example: Asphalt roads need constant maintenance, while some dirt roads have been in continuous use for decades or even centuries with minimal to no maintenance.
Further exploration:
• Google “vine bridges”; “rope bridges”; “living bridges”
• Book: Lo-TEK Design by Radical Indigenism, by Julia Watson. “TEK” stands for Traditional Ecological Knowledge.