If I give you the IPv6 address to my desktop computer, you still can't transfer a large file to me or try to video call me.
The reason is I haven't configured my firewall to let any of those things through. IPv6 or IPv4 NAT is in the same boat.
The reason is I haven't configured my firewall to let any of those things through. IPv6 or IPv4 NAT is in the same boat.
But if your computer had connectivity to the rest of the network, you could choose to disable protection on some port, and help bootstrap some software like those. Instead, with NAT, you can't.