At the end of the day are there really enough ULR routes in the world that make these sort of 19-20 hour sectors viable. Maybe for Qantas because LHR and JFK are at the end of them but Australias not a very big place people wise and pretty insignificant globally . same with SIN-JFK, I mean Singapore the country isnt much bigger than JFK the airport.
If you have to upgrade Y -more pitch etc it means the aircraft is even more niche . So yes it means nowhere in the world is unreachable but how many really big city pairs are there longer than 12 hours ?