From the blog post
obtaining an ARIN ASN and a portable /24 IPv4 block for a home networkI’ve wanted my own Internet address space for a long time. Not “my ISP gave me some statics” space which I’ve had for well over a decade now, but a block that belongs to me, announced into the global routing table by equipment I own, and ideally sitting in the rack in my house. Type the prefix into bgp.tools and see my own ASN sitting there as the origin. How cool! (ok, cool for some, but not most)
Why shouldnt they if you have enough ips? Nat still is an ugly workaround
Workaround to what? Why would radarr need a public-facing presence?
And even if there is a use case, the routing alone would be a nightmare.
ipv4 exhaustion. Devices are meant to have routable addresses. How would that make routing harder?
Ipv4 TLD exhaustion happened in 2011, but it was functionally impossible to get a public IP directly from IANA closer to 2005.
And the routing would be a nightmare because if you have multiple gateways between non-overlapping CIDR ranges, you need to tell routing equipment how the packet should return to its source.
So ignoring there being no reason to expose sonarr or radarr to the public at large in the first place, you would be working with two potential scenarios with multiple IPS: either you have two distinct subnets blocks behind your gateways, or you you have two gateways to a single subnet.
In the first case, you would have to route traffic between the two subnets, which makes the scenario not make sense, because why would you need packets between two local hosts to pass through their gateways through public space when they could just be in the same subnet. In the second case, you would have to specify to all your internal hosts two gateways so traffic know which public IP to return to.
Neither of these scenarios make sense when NAT is a much simpler (and cheaper)solution.