There is no difference between Raiders and Cowboys.
They are both too far for a day trip for most fans (how far doesn't matter, and if it does there should be a clear rule about it not this wishy washy made up as we go nonsense).
Canberra is not Sydney. Canberra is not in NSW. It's the capital city of Australia ffs and not allowed to host a final.
If the NRL was fair (we all know they aren't) the rules would be the same for Canberra, Newcastle, and Nth QLD. Either all play in Sydney/Brisbane or none do.