It is the first ever far-side sample-return mission ever (and I think only the second far-side landing at all, the first being Chang'e 4 in 2019), so there's ce

It is the first ever far-side sample-return mission ever (and I think only the second far-side landing at all, the first being Chang'e 4 in 2019), so there's certainly some non-trivial element of "doing something no one has done before". And the far side is somewhat geologically (selenologically?) different to make that a useful scientific thing rather than solely for bragging rights, not that those aren't in the calculus with these things. Chang'e 7 will be pretty interesting as it's going to Shackleton crater, which is a hypothetised water source (though evidence of surface ice is pretty weak) and has never been explored other than orbitally and an impactor from Chandrayaan-1.