My team is about 20 days in and having a similar experience – many players (including myself, who founded the server) getting bored, because it wasn't quite clear what they were supposed to do.
But I'm not sure that extra environmental challenges will fix the problem.
I think there's a combination of problems that are hard to address:
- Some professions naturally feed into the endgame. (i.e. mining -> smelting -> mechanics -> electronics, whereas tailoring just sorta... ends AFAICT?)
- There's sort of a "decisionmaking bottleneck" where you need some people to plan out how everything fits together... but you don't actually need ALL players involved with this process, (really no more than 2-3). So then you have a bunch of people with nothing to do but manual labor. No creativity or agency. This isn't actually fun (esp once you've done it a million times).
We also found that in the first half of the game, each player had their own house to build and needed to afford good food. But later in the game we had plenty of food, houses were basically built, and then there wasn't that much to do that you could do independently, instead of everything was tightly coupled into a single monolithic project (which, again, only a few people needed to do the planning for)