Oh yes, that's really convenient for home users. "Install this thing on several computers and keep it in sync or you're not qualified to have a network"
Home users would ideally be served by things like mDNS and LLMNR, which should just work in the background. If I want to connect to the thermostat I should be able to just go to http://honeywell-thermostat and have it work. If I want to connect to the printer it should just be ipp://brother and I shouldn't even need to have a DNS server.
Your interface has a default gateway configured for it, doesn't it? Isn't that default gateway the router? NDP should show the local routers through router advertisements. There is also LLDP to help find such devices. LLMNR/mDNS provides DNS services even without a centralized nameserver (hence the whole "I shouldn't even need to have a DNS server"). So much out there other than just memorizing numbers. I've been working with IPv6 for nearly 20 years and I've never had an issue of "what was the IP address of the local router", because there's so many ways to find devices.
Even then nobody is stopping you from giving them memorable IP addresses. Giving your local router a link-local address of fe80::1 is perfectly valid. Or if you're needing larger networking than just link-local and have memorable addresses use ULAs and have the router on network one be fd00:1::1, the router on network two be fd00:2::1, the router on network three be fd00:3::1, etc. Is fe80::1 or fd00:1::1 really that much harder to memorize than 192.168.0.1 or 192.168.1.1 or 10.0.0.1, if you're really super gung-ho about memorizing numbers?
> My DNS "server" is a router which can "add" static entries...won't work with dynamic addresses.
Sounds like a pretty poor setup, systems which could auto-add DHCP'd or discovered entries have been around for literally decades. You're choosing to live in that limitation.
> What redundancy, multiple servers?
Multicast name resolution is a thing. Hosts can send out queries and other devices can respond back. You don't need a centralized DNS server to have functional DNS.
If it breaks, so much that you cannot do a dig, you need to re think your network.