The Internet is governed by a single algorithm: IP routing. Short IP addresses are a lot easier than short cryptographic addresses.
Adding 16 or 32 more bits to IPv4 would have been trivial. The existing IPv4 address space becomes 0.0.n.n.n.n or perhaps 0.n.n.n.n.0 if you wanted to give every existing IP 256 addresses to assign while also multiplying the IP space by 256.
You're describing 6to4, where the existing IPv4 address space becomes 2002:nnnn:nnnn::/48. You can treat the 80 bit suffix as 8 bits when designing a network.
Problem is, stacking the new protocol on top of IPv4 was never very reliable, so 6to4 is mostly dead now. It would've worked a bit better if the Internet had used 2002::/16 exclusively.
Adding 16 bits or 32 bits doesn't matter: The networking stack of every device would still need to be updated to understand the new address structure (just like IPv6!) You can't magically fit 48 bits in a 32 bit field.
IPv6 was the correct long term approach. You wouldn't want to pick only 48 bits and have to do this again in 20 years.
Yes. I'm saying if we had to update every device anyway, we might as well do it right and not some short term solution (48-bit addressing or whatever.)
Adding 16 or 32 more bits to IPv4 would have been trivial. The existing IPv4 address space becomes 0.0.n.n.n.n or perhaps 0.n.n.n.n.0 if you wanted to give every existing IP 256 addresses to assign while also multiplying the IP space by 256.
Easy, easy, easy.