great job with the technical details and understanding all this. But I like this quote:
"IPv6 is a 1990s solution to a 1980s problem, designed by committee before we fully understood how the internet would evolve. It solves address exhaustion, but creates more problems than it fixes — and doesn't align with how modern networks actually work."
IPv6 was designed under the assumption that:
NAT was bad
Every device should be globally addressable
Hierarchical routing and massive address spaces were the future
But the internet evolved differently:
NAT enabled firewalls, local network segmentation, and privacy — it's now a feature, not a bug.
Global addressing is a security liability, not a benefit. Nobody wants their fridge on the public internet.
Most real-world networks are flat, dynamic, and heavily virtualized, not rigidly hierarchical.