Tragic heroes and anti-heroes work for *grownups,* not *kids.* This ain't Batman. Or even the X-Men, which can afford to be dark and dreary, because that's the thematic element of the franchise, and is aimed at more mature audiences. The MCU is, for now, the four-color wing of comics, and it owes all its success to keeping the tone optimistic, bright, fun and funny, instead of getting all grim and gritty. Tragic heroes and anti-heroes do not belong in this type of CBM. (Once Marvel figures out what to do with the motherlode of Marvel Knights-type characters in their harem, that becomes a different story. But for now: four-color.)
There is absolutely no scenario where any of the heroes come out looking good --- or *profitable* --- if they betray each other, backstab each other, try to kill each other. These are superheroes....these are role models. Kids don't want to see their role models turn into ***** and punching bags and villains.
Again: the ONLY freakin' way a Planet Hulk/WWHulk scenario works is if the ones who kick him off the planet are bona fide villains. World Security Council: yes. The Leader: yes. Thanos: yes. Tony Stark, the Avengers, and any form of "Illuminati" that involves superheroes: hell to the ****in' no. Never.