"Why I don't regret my abortion"

Not happier for it; that's a strawman. It doesn't have any need or use for happiness, given that it does not have the hunger for happiness (being that it does not have consciousness). Happiness only has any value in relation to the threat of deprivation of happiness. It only has any value once you've created the conditions wherein the sentient being can feel deprived of happiness.

What you would put forth as the benefits of being born is, in fact, nothing more than an array of imperfect solutions to an unnecessary problem.