Incarnates just exist to either fill in the holes of inherent problems with your archetype or powerset, such as endurance issues or a lack of damage, or exist to make you better at what you already do. You hardly trivialize any content, especially not long term rewarding content. You may be able to solo +4/x8 Council or something easier in a radio mission, but it still takes a proper build to do something like solo an ITF. A proper IO build without incarnates will always outdo someone on standard IOs but fully incarnated. They're a minor boost, if anything.
I still want a brute or tanker for Statesman/Miss Liberty Task force, as well as LRSF. They're still a near necessity for Hamidon raids. All this doomsday talk does is hold back game development and forward progression.