Re: Are we really running out of IPv4?
Fortunately, we can go back to the mailing lists where the designers of IPng debated their ideas. [1] [2] As far as 128 bits is concerned, there were arguments that the address space should be large enough to accommodate any imaginable usage, especially because the opportunity to increase the address space again might not come around for a long time, if ever.
[1] https://www.sobco.com/ipng/archive/big-i/index.html
[2] https://mailarchive.ietf.org/arch/browse/big-internet/