I don't think there is a breakthrough solution that makes everybody happy. In fact I think I can prove that no such solution exists, but I'll leave that proof as an exercise for the reader ;-)

I think we can go in many directions as once without damaging nostr or interoperability:

1. Some relays can block giftwraps.

2. Some relays will AUTH giftwraps and know who sent it (or at least who paid for it).

3. Some relays will have some out-of-band LN or e-cash like payment system for giftwraps.

4. Some relays can specialize in giftwraps, offering a paid service, where the recipient is charged (not the sender), storage is capped per user, and the recipient is responsible for cleaning out space if they get clogged with spam giftwraps.

5. Someone will setup a giftwrap mix network so that relays cannot know who wrote the giftwrap, because for some hyper-sensitive giftwraps, lives may be on the line and it is very important that the government cannot compel the relay operator to tell them who wrote it.

I don't think having all these options at the same time is a bad thing. I think it is a good thing. It is a competitive landscape. They all interoperate well by following the NIPs. And if they don't, we need to know that and modify the NIPs so that they will.