You guys are saying that endgame content would be played by 1% of the people because it is too hard, just like eidolons and deimos vault runs can be pretty hard for new players, but they get there if they stay playing the game, I feel like the majority of the people that play the game already have decent builds, but most of them stay just grinding for new weapons and warframes because there is literally no reason to get more damage.
If you give these new bosses a warframe drop, a new weapon drop, and new arcanes or something similar, it would be just like any other update for the game but with an actual new mechanic/gameplay, that way you guys get what you want, something new to grind for.
You guys are also saying that separating people takes the group aspect out of it, but no, TESO has done this several times in their dungeons/raids (And I'm pretty sure that other MMOs have done this as well) in certain stages of a boss fight, you get transfered to a different place where you have to kills mobs to get back to the main boss stage. This works even better in warframe, where your weapons don't need any buffs from your warframe to be able to do decent damage, and just make these mobs killable with a good weapon build, this way you can even aim for a Tank-Healer/Support-DPS group setup, so it becomes even more entertaining.
Someone said that archons were hard until they found that with an specific build they can one shot, so in this case, you just have to make these bosses better, they need to figure out resistances, HP, armor, shields and everything, and balance out these dumb af builds.
Or have mods and everything balanced for these bosses, just like other games do for PVP. Hell, take Path of Exile as an example, you can kill pretty fast any endgame boss with they require mechanics or you get oneshoted.
I'm not against oneshots, when they are done right, with well telegraphed attacks, you can avoid them, that's part of learning a new boss mechanics.