I assume this is referring to SLAAC? SLAAC is...fine. Most managed networks will want the extra control offered by DHCP though and DHCPv6 is currently in a much much worse state than DHCPv4. Also a single interface having at least 2, usually 3 or more (link-local, autogenerated, privacy) v6 addresses on the network is definitely not simpler in any way. Also clients still have not figured out which configuration methods they should actually support - Linux network managers generally default to SLAAC-only and DHCP needs to be explicitly enabled, for Windows setting managed flag in RA works, I believe. Android does not support DCHPv6 at all.
> network renumbering and router announcements when changing network connectivity providers.
Absolutely not. Network renumbering is a breeze when all you need to change is the public address of your gateway and the local network keeps the same local addresses. Prefix translation is awful and no firewalls have good tools to handle changing your v6 prefix.
> It simplifies processing of packets in routers by placing the responsibility for packet fragmentation into the end points.
With respect to fragmentation - yes, but overall this statement is blatantly false. v6 packet processing by routers is much much harder due to the variable length headers.
> The IPv6 subnet size is standardized by fixing the size of the host identifier portion of an address to 64 bits.
Ok, this one is true. Not entirely sure why the author considers this better, but sure, I'll agree.
To add to this, what I would like to see in IPv6 personally:
1) Ability to get a personal prefix as a private individual or a small company (not a LIR or LIR-sponsored)
2) Ability to use that prefix with any ISP I choose - similar to how a consumer can migrate their cellphone number to a different provider.
3) RFC 6275 actually implemented
There are other bits and pieces, but I believe if these with 3 things were done, IPv6 would actually have a "killer app" which would make a strong argument for migrating over to v6.
> the local network keeps the same local addresses
If you need that, you can assign local addresses from the ULA range. No one is forcibly taking your local addressing away. Now, yes, the "V6 ideology" is about globally routable public all the things, but you don't have to follow it.
1) You generally do not need prefix delegation in v6: you use IPv6 like it has been designed too: routable address everywhere, /64 per default and prefix over it.
2) SLAAC is stateless and deterministic: One MAC address will always gives you the same IP. That makes DDNS mostly useless.
But even if you really want to do it, it is also possible with SLAAC.
1) Precisely because you are not supposed to use NAT with IPv6 you need prefix delegation: CPE (home router) in addition to an external address (can be obtained via SLAAC) needs a network prefix (/64 or more) which it can use for LAN segment(s). DHCPv6 PD is also used in 464XLAT.
2) Address with SLAAC is deterministic but you need to know MAC address for each device to generate DNS zone. In home LAN I don't want to maintain a database of MAC address for all devices (with internet connected everything there are quite a few of them) and also at home I trust my devices not to spoof hostname in DHCP request so DHCP based DDNS works fine for me.
It simplifies processing of packets in routers by placing the responsibility for packet fragmentation into the end points.
The IPv6 subnet size is standardized by fixing the size of the host identifier portion of an address to 64 bits.