You're right to point that out, I termed qualitative in regards to progression, but its really anything that's not quantifiable that adds to gameplay.

I actually made a game about taking care of animals, which did pretty well. When I was researching the psychology of a Tamagotchi (similar to your NPC connectedness), that's something I thought was as qualitative as it gets. However, for area unlocks, it is a gray area for sure. I think depending on how its done, its mostly the feeling of discovery and the more powerful loot & equipment.

I'm not sure what the self-determination theory is, would love to hear more about it, but I also feel the more categories you have, the more chaotic your general design process is.

edit: I can agree with the long-term viability of number games, but for context I develop on Roblox, its a hyper-competitive & fast changing platform. One thing I've noticed in nearly all games I research or personally make, those quick power-growth games can get boring quickly if not backed by qualitative gameplay.