Some of the biggest complaints I've seen for the new campaign in TWW3 relate to how players don't like being pulled out of their conquest experience by being forced to participate in the chaos realm race. Personally, I do understand some of the gripes, and although it might be novel to participate in the chaos race campaign once for the experience, I can't really see myself doing multiple play throughs of it.
But honestly speaking, I have no idea why CA didn't just give a victory condition option in the campaign settings so that we could choose what kind of campaign we want to play. Give us a conquest victory condition that disables the narrative victory, and give options for short or long campaigns that determine how many settlements you need to conquer. Hell, maybe throw in an annihilation victory condition while you're at it.
You could also add a setting that allows us to tweak whether to enable or disable the chaos portal spawn for other victory types (it might be nice to have the option to go into the chaos realms purely for their rewards or for fun, but not be forced to do so when it's not convenient).
Frankly, there shouldn't be a need to wait for Immortal Empires for people to get a sandbox campaign experience. It could have been an option right from the get-go, even for the current campaign map. I feel like this was a massive oversight.