I think there are considerable reasons for a spiritual successor to be made for a game like SH5. The mega mod helps but SH5 is still a game that was rushed out of development and is unsupported by the publisher. On top of that the publisher is toxic anyway.
If a new project was started by some devs that want to work on it there would be a whole host of benefits if said project was successful. For starters, it would be just that, something that is supported by a team that wants it to succeed. Secondly, it would benefit tremendously from running on a newer engine with all of the bellls and whistles that would entale. I could see Unreal Engine 4 being a great fit. A game like SH5 wouldn't be doomed from the start because of its size or complexity. That has nothing to do with it, it would be completely up to the skill and determination of the dev team.
Finally, I don't feel that money is the limiting factor. There are plenty of free or cheap ways to get things made, or at least to get a good working prototype that could be presented in a kickstarter to attempt at getting funding. Unreal Engine 4 and Unity are awesome game engines that are completely free to use. The limiting factors are designers, artists, and developers who are willing to undertake a project.
Sorry to post late on here but this is exactly what I have mentioned before in this forum. Also I am a game designer so it caught my eye and made me want to throw my two cents at it
