Wait, the "chapters" thing? They don't really solve the problem. I enjoyed the base game, but is it worth it to spend multiples of what I spent on the base game just to add a few new mechanics? And still not have most of them? As against spending the same money on a (several!) new game(s)?

Ah - to be clear I think the sub thing is only on other PDX games at the moment (e.g. EU4). They've not done it/tried it for CK3 yet. Tbh with CK3 a lot of it comes down to the base game being absolutely fine. But if/when you want MORE, the DLCs are there.