Another option (depending on your requirements) is to use normal "workstation" Linux distro like Debian on an regular x86 PC equipped with two NICs. I added an SFP28 dual NIC to an old gaming PC and now use it as a router/home server and can saturate the link (25Gbps). I get north of 4Gbps through Wireguard too. Routing and the firewall are built into the kernel so you don't really need a specific distro. I just added a DNS server (Unbound in recursive mode) and a DHCP server. For WiFi I use hostapd, but an external AP would be a better solution for most people.

Did you manage to get IPv6 prefix delegation working with dynamic prefixes? Best solution I found involves scripting to re-build config files and restart a daemon, where OpenWRT just does it out of the box.