Yes, yes they can go without him. It's why all of the games not featuring the Chief were still a success—because they can go without him. If 343 were capable of creating a compelling character who people actually wanted to play, people could go without him a lot longer. As is, killing him off and not being able to replace him isn't going to make people want to keep playing, it's going to make people want to stop buying. Out of the ten Halo games currently out, three of them solely focus on Master Chief (Halo: CE, Halo 3, and Halo 4); it's not even feasible to argue that he's holding back further exploration of the universe. It makes zero sense to kill him off.
It makes perfect sense else you'll have people clamboring for him to be back as a protagonist while he's alive. Furthermore killing him off has nothing to do with getting a better story, but a chance to explore other stories entirely without the chief being involved or brought up as you Branch out. You know why reach could get away with it? Because it's a spin off and not a mainline game, what happens when 343 try to set a new series? Can people go 3 or 4 games without the chief? This is why he can't be around cause he will be brought up.
Chief needs to go as is, there's much you can do with a Halo setting and various protagonists that can come out of it.It makes zero sense to kill off such a well established protagonist just because they want to focus elsewhere. Halo 2, Reach, ODST and Wars have all proven that it is in fact possible to tell a story that's not about Chief without killing him. Killing off the main character isn't going to suddenly make 343's Halos good, least of all when arguably their best work was almost entirely focused on The Master Chief. All you need to do is look to Spartan Ops and Halo 5 to see how well an original cast of 343 characters will turn out.
If people weren't so attached to him, I wouldn't see a need to off him as a character.
Not feasible yet Halo 5 shows just that. Why is 343 promising to feature him more after the backlash if he isn't holding further settings back? As I said, reach worked cause it's a spin off and not a mainline game, what happens when 343 goes multiple games without him? The attachment to chief is the issue here as even if there are compelling characters, people still aren't going to want to not play as chief. Why is it an attachment issue? Cause when I see statements like the chief "is Halo" there's going to be issues trying to Branch out.
You mention games without him being successful, but I'd like to hear how so? Halo wars sells like crap when compared to the shooter side of Halo (one to two million), it sells fine when you compare it to other RTS console games but when matched vs the rest of the franchise it's not even close and shows most fans of the franchise don't even acknowledge it. How about Halo reach? It's a shooter so it's already going to compare much better with the rest of the series as it's a shooter franchise. Did it sell like crap? No. Where did it's success come from? Well for one it came out right after Halo 3, still had the bungie brand making it and was marketed as a spin off to try a new Halo experience. I don't see how it could fail when you consider all of that. What about odst? Also marketed as a spin off but also had a crowd wanting to see the experience from an odst perspective, even then it sold half of what H3 sold, for a spin off it did good.
"Out of the ten Halo games currently out, three of them solely focus on Master Chief (Halo: CE, Halo 3, and Halo 4); it's not even feasible to argue that he's holding back further exploration of the universe. It makes zero
sense to kill him off." Sure only 3 games solely focus on him, but how would H2 have done without him entirely? Or Halo 5? Both games came under criticism because of not featuring him and only him. Why did they even get criticized for it? Because they're part of the mainline series wouldn't you agree? This just reinforces my point "chief is Halo" from earlier.
"People will stop buying" I mean people have already been doing that with the spin offs, Halo wars doesn't even compare at all, odst sold half of what H3 did and Reach is the only one that even came close in matching up between two mainline games. Furthermore it's not like the mainline series hasn't been dropping in sales anyways right? The estimation for H5 is 5 million, the lowest it's been since the very first mainline game. Is there anything to lose? If it costs more in sales in a franchise that I already think is falling off a cliff I have no issue with just dropping even more if it means a new setting with a new cast comes out of it. Sometimes destruction is in order to rebuild which I ultimately think is needed. So you're quite right people will not buy but that's already been proven with the games not featuring him 👍