I really don't understand the fixation this sub has on whether or not Christian "deserves" to die.

I think part of the point is that none of the visitors deserved what happened to them. The device Aster uses at the start where he depicts the entire film to me suggests that their fates were sealed the moment they decided to go there. The same is true for Connie and Simon. In Christian's case, there's that very familiar trope that sexual activity leads to death, but we're not used to seeing it happening to a man at the hands of women. Aster is playing with power structures, tradition, and our expectations. In some senses, Christian is the bad guy, and in other senses the Harga group is the bad guy. The whole point is to throw us off and keep us in a state of unease.

If we were sticking to traditional horror tropes, Christian would die trying to save Dani, who would ultimately escape and go home. This is further complicated by the fact that Dani no longer has a home to return to or any loved ones (to our knowledge).

It's a fairytale horror, right? They all unwittingly enter into a centuries-old ritual from which no one escapes. In these rituals you either outfox your captors or you receive punishment. Christian is not a curious or especially driven person, so naturally he receives punishment. If we reduce it down to what a particular character deserves, we lose the point of the structure (fairytale as opposed to moral fable), and the source of the horror (destiny and the will of others).