We don't know the extent of the elves magic, but isn't this current system way more complex than just letting people become women whenever they want?
Yes, yes it is.
The system is deliberately made complex in a way that couldn't be a mistake, and has to be a way to encourage violent people to build giant harems...
Why you think this is depends on whether you're wearing the Doylsian or Watsonian hat, but it's either the author's desire to make a gag genderbending harem comedy and have some sort of explanation for why, or "because elves did it" to blame.
That said, it does seem a pretty strange path to take to make up this crazy complex system just to then immediately try to get everyone to tell you it's shit and hate it.
As the others said, you only have to look at the results of such a system to see that it doesn't exact matched the stated purpose claimed by the Elves. Is it sinister intent on their part when they took control of human's reproductive system and force all future born humans to play their game, or is it a combination of their rules being poorly thought out and the human tendency to twist rules themselves?
To me, what I see is both indoctrination of humans favouring the Elves (they control what is "legal" marriage and who can have children) and the selective breeding / sexual selection of more militant and aggressive humans, who can pass on more of their genes because better warriors under the system gets more partners. Also, each human gets two lives and can double their genetic diversity by switching between male and female. The humans may be slowly turning into a soldier race of the Elves.
That, or we're all taking a comedy genderswap series way too seriously, lol.
PS: Atlanta is the product of an egg-holding human and an "eggless" elf. He inherits an egg. How?
It would be taking it way too seriously if there weren't obvious attempts to be doing really serious worldbuilding, including having whole pages dedicated to big lists of rules and two chapters in a row without any of the major characters just to do more worldbuilding. The overall tone is clearly comedic, but when someone then stops the show to pull out schematics for all the custom cars they're driving, the history of the car models, and how each of the modifications they have done to their cars affect performance in their own individual ways, then getting into motorhead talk is perfectly justifiable and encouraged by the text.
... That said, the more I think about this, the more I'm dreading that we're going to get to the end, and the elves' big plan turns out to be, "Ahh, we like it when big strong orc-san rapes us, so we wanted to make a system where only the strongest and rape-y-est human men would be bred!"
I suppose when you put it that way, all this worldbuilding must be setting up for a big payoff in the end. One we won't see yet for a while though, given the pace (sorry).
The only elf we've met thus far is an invisible stalker who apparently only Atlanta could see (end of Tucker and Charlie's story), strongly implied to be secretly keeping tabs on humanity. The human Kingdom is also reliant on technologies from the Elves to protect themselves that the humans have no idea how to fix if they break down.
I really doubt the Elves are just doing all this elaborate stuff to bred themselves husbands, though I can't eliminate the possibility due to its sheer absurdity.
... That said, the more I think about this, the more I'm dreading that we're going to get to the end, and the elves' big plan turns out to be, "Ahh, we like it when big strong orc-san rapes us, so we wanted to make a system where only the strongest and rape-y-est human men would be bred!"
They'd be disappointed since it seems like really, the most cheapshooting people win. Which would be the kind of thing the elves would deserve.
As in the God Hand song: "don't act like you don't like the Ball Buster"
If we wanted to defend the complicated and obtuse nature of the elfs' system, it is worth keeping in mind that this is all a reaction to the dying curse of the Demon King. They didn't just decide to implement this out of nowhere; we are told that this is the best workaround to the Demon King's curse they could devise. Maybe unlimited at-will genderswaps or whatever wouldn't work, maybe they tried it and the curse blocked it. Maybe this complicated, headachey, and terrible system genuinely is the best that could be of an unmanageable situation.
If we wanted to defend the complicated and obtuse nature of the elfs' system, it is worth keeping in mind that this is all a reaction to the dying curse of the Demon King. They didn't just decide to implement this out of nowhere; we are told that this is the best workaround to the Demon King's curse they could devise. Maybe unlimited at-will genderswaps or whatever wouldn't work, maybe they tried it and the curse blocked it. Maybe this complicated, headachey, and terrible system genuinely is the best that could be of an unmanageable situation.
Although the jaded reader in me also says the key term there is that we were told, not shown, that it was what they had to do in response to a curse by a demon king. Told by whom? Just because the narrator spits that out in the intro doesn't mean there can't be some twist reveal that this was all the elves' plot all along, and they just srpung it out after the demon king was defeated, and used it as a convenient excuse when the whole curse was the elves' doing, as well.
The part about "losing your egg if you switch genders too much" doesn't seem to be a feature so much as a shortcoming of the power of the elves, so "unlimited at-will genderswaps" was probably never in the cards, but there still isn't much reason why they have a system of dueling in the first place when you could just as easily have made it purely a "voluntarily give up your egg to become a woman" system that is a one-way ticket, or maybe still include a way to change back.
Rolo continued to think of Juri...And in her heart she continued to solemnly swear...The only thing that matters is staying true to your original beliefs, and continuing down the path.Although...she's already used to being a woman now...On the road of revolution, right or wrong no longer feels quite as important.In order to see tomorrow.Regardless of whether she could ever regain her freedom or not...To continue to love Juri for ever...Or regardless of whether she'll ever have Juri's egg again.