Given that Third-Class Space is so important, obtaining such a "world fruit" should be a cause for celebration, right? So, where does Li Xu's dissatisfaction come from?
As previously mentioned, Third-Class Space is a product of an Anchor's exploitation of First-Class Space, much like doing a "second creation" on a complete painting. This kind of second creation leads to two possible outcomes.
The first outcome completely changes the original painting beyond recognition, where a cat is no longer a cat but has become a mouse, or something else entirely, in any case greatly differing from the original painting.
As one can imagine, this painting is no longer the one defined by the wishes of all beings and naturally can no longer receive wish power from the real world. This situation is what is meant by "Anchor Loss."
The Anchor is the wish power, the connection between the fantasy world and the real world. With such a connection, it qualifies to navigate to the real universe.