OK? The Internet does not use OSI, but it sure was helpful just now as an educational tool for describing that "what layer a VPN operates on" can be confusing. Even if you don't literally use OSI layers, knowing that UDP builds on top of TCP and having a common vernacular to express that is pretty useful. Given that the entire thread was already using specific OSI layers (which have clear mappings to things the Internet does do), starting by saying "the OSI model is not what the Internet actually does" does not seem to be the most productive avenue towards fostering understanding :)