In some cases different devices on a segment need a different default router (for default). This is the fundamental
This capability is also defined, "more specific routes" - but no one encouraged any vendors that I know of to support it - so they don't. Big demand?
problem with RA's, they shotgun the entire segment.
As opposed to a standard deployment, where the DHCP server provides the same information to every host on that link ... ???
What would be useful would be having the option to give a default router to a dhcpv6 client, and having vrrpv6 work without RA's.
These are separate problems. Host configuration vs. first-hop redundancy, and we can solve them independently.
Why can't we have those options in our toolbox in addition to this continuously evolving RA+hacks?
You say hacks, others see it as relatively-speaking simple additions of more functionality. You can define any options you want for DHCPv6, write a draft and get community support. I don't see how that ("continuously evolving DHCPv6 hacks") is any better than what is happening with RAs? I, for one, am just fine with RAs being the first step - leading to either SLAAC or (some mode of) DHCPv6 ... /TJ