-Easier birth control: Make the egg into an omelette
-Relaxed child support laws: Requires deliberate decision to incubate the egg
-Clean packaged periods: Egg = No mess!
Although, there would be stories about partners hiding fertilized eggs: Instead of unplanned parenthood we would have unconsensual parenthood
There’s probably more nuances I am missing. But do discuss it in the comments.
Ops focus on a singular “nicely packaged “ egg made me unable to consider anything else then bird eggs.
I was so confused by your comment, i had to look it up.