it doesnt but you dont have to worry about monogamy-only rules like dont do this and dont do that, which is exclusive to monogamy. which makes it objectively worse since you dont have to worry about that in other relationships.

All of the others - short of anarchy - also have their rules. For example, polyfidelity is nearly identical to monoamory except you now have to consider the dos and don'ts of both of your partners making it objectively more complicated than monoamory.

Having had both types of relationship. This is such backwards thinking, with most poly relationships you will have to make severe sacrifices to the time spent with most of your partners, and often end up with more non romantic relationships. Breakups are more complicated. Not to mention how much more communication it requires to keep together. Calling that anything but a major compromise is just lying. I am not saying any type of relationship is more valid. But that they all come with different compromises which work better for different kinds of people. Just because it works better for you doesn't mean it does for everyone.

That's not a rule to get around, its called respecting your partners wishes. Its a basic common decency regardless of how many partners you have.