Permissions require you to make an open-ended trust decision in an entity.

"Do you trust this entity in perpetuity in an open-ended way with this data" is obviously an impossible-to-answer question.

There structurally is no good answer to that question.

We shouldn't have to answer that superficial question, we should just have to answer the more fundamental question about what we're OK with our data.

That would require changing the physics of trust.