I'm a huge critic of the hakama, and of its related bane - sawari-waza.
I've been given many reasons over the years, from fashion, history, tradition, hiding footwork, managing strides... In the end, I look at it as practical as the human appendix: we all have one, no one knows why, but you better care for it or else.
I'm in Aikido for self-defense. I don't wear hakamas outside the dojo, so, any benefits of it hiding the feet or managing stride are not applicable to me.
In our school, we wear hakamas starting at 3rd kyu; but we attend seminars, and there, it's common to find schools who have all their students wear the hakama, even kids; while others insist only when 1st dan. So here, vanity seems gone: you can't readily tell who's who in a crowd of mixed formalities.
I'm no fan of sawari-waza, either (who is??), and wearing a hakama when performing it is insanely difficult - so much so that I find myself worrying about ripping the hakama or dislocating a toe than I am about my technique.
I've been in martial arts for almost 40 years, and only in the last 10 years have I begun to wear a hakama, and, when comparing what I've learned in Aikido to what I've learned in Taekwondo, Karate, and Hapkido, I see no practical use for the hakama. I don't even like traditional gi/dobok because such isn't a part of real life, although, they do provide something that makes it easy to train in, and translating it for outside-the-dojo is a lot easier to do than with a hakama.
So no, I don't think it adds to one's training.
But not everyone is in Aikido for self-defense. The more recreational schools teach for more historical reasons, much like Medieval Times knights wear plate mail when jousting. It's because, that's what they used back then. Or revolutionary war re-enactors, why use muskets in re-enactments when one could use an M16? It just wouldn't be historically accurate. So same for hakama, I think.
So in this case, perhaps a hakama would be more useful in this context.