There are a few issues with your thinking
> Point 1
> The game is on ancient hardware, it will hold back the scope of the game, i understand making a new engine if it was exclusive to the series x but for the xbox one too? just upgrade the halo 5 engine it was perfectly fun and even THAT had to be downgraded to run on the OG xbox one.
Not really. There are ways to cutback various areas without hurting the scope of the launch product. We see these cutbacks in the beta on the One and the One S (resolution, detail, fps). The H5 engine was also still the Blam! engine (so is infinite but ill get into that). In the state H5 was in, Blam! was not very flexible and had major scaling issues. This is why variable resolution was so wonky in H5. We also know Blam! in that state was hard to work with and was full of spagetti code that made working with back end changes almost impossible. Since infinite was going to be built as a platform and not just a new title, it had to be reworked and using H5’s version would not of worked
> Just use unreal engine 5, seriously even crysis 3 which is ancient by now looks way better than the slipspace engine, just use unreal 5 folks it will look better, it will play better and be optimized for the latest hardware and best of all its completely free! well its too late now… but maybe for halo 7, dont see the fuss for a new engine when it looks so average titanfall2 type visuals.
Ive seen this a few times but people making it don’t actually know how engines works usually. Engines are not just for visuals, they all posses the tools and plug ins needed to do a variety of things in order to make a game. Creation engine lacked comprehensive animation tools, which is one reason why the animations were always kind of meh in those games. There are reasons for why it lacked them of course but thats not the point of this.
Halo has a specific feel to it. It has had it since CE and whether people want to admit it or not, has even had it in 4 and 5. Sure those games had other systems piled on top of it that made the gameplay feel different, but if you stripped that away, there was a feeling there only halo has. Source is very similar. Source has various physics systems that are specific to that engine and are extremely hard to replicate outside of it. Transitioning to UR 5 =/= the halo feeling will be able to be 100% replicated given the tools and pieces being used are not and or are not similar to the ones that were used to make Halo in the first place.
Also, again, engines are more then visuals and thinking their not is extremely ignorent. We don’t know what the back end looks like for slipspace (which is the Blam! engine modified to the point of it needed to be rebranded). However, if we look at Destiny as an example, it uses the Tiger engine (which is actually also a severely modified version of the Blam! engine). They recently reworked various tools in the engine to make development more streamlined which is why content was removed from the game so they could start porting it all over to the new frame work. The new version “supposedly” allows them to make quicker changes and additions compared to the previous Tiger version (which is now known for being extremely difficult and slow to work with). Slipspace, based on what the devs have said, appears to be something similar where there are major tools changes and backend changes to allow for quick implementation of changes and additions that are specific to Halo.
As great as UR 5 is, there is no gauruntee it would fit the needs of Halo.
> Point 3
> waste of time and money see MGSV. alot of fuss was made about metal gear solid 5’s fox engine, and it ultimately held the game back, konami even ended up ditching the engine for unreal 5 after a couple of games. Essentially sunk costs for little return. There’s little point in developing expensive engines these days folks when unreal engine 5 is free for all to use.
Making a new engine is always a gamble because of this exact point. It can be a sunk cost but in the case of MGSV, there is more then just “engine issues” that lead to the changes. Kojima had a falling out with Konami. Thats a huge factor in a lot of the changes that were done and given the shift to focusing on PS platforms, the benefits of Fox were not longer viewed as needed (main benefits being the ability to stream line cross platform development). Having an in house engine is always way more beneficial then using a third party given the devs have direct control over the entire system. If something does not work, they can go in and make the needed changes instead of trying to force and engine to do things it was not meant to and or involving a third party. Dragon Age Inquisition, Mass Effect A and Anthem are perfect examples of this where they are to be in contact talks with Dice in order to get frost bite to even work for their games (and it did not always result in a good ending).
Of course the counter would be “well other MS devs us UE and are using UE 5” and you are 100% right. However, those devs have almost exclusive exoeriance using UE. The coalition has only worked with UE and are considered some of the masters of said engine. Ninja Theory has been working hand and hand with Epic when it comes to various breakthroughs in animation using UE including real time rendering (used for HellBlade 1). All these devs have extensive prior experiance. 343 only has experiance with Blam! and the variations of Blam!. The issues with Blam! were similar to that of Tiger (makes sense). So 343 did what bungie did and made a sister enginer to Tiger with more bells and whistles that will support their needs and plans for the long term goals of the Halo platform.
Realistically, making slipspace was the best option. We can only wait and see on how it pays off.