Eh, I think that production committee is fine, even more because those companies are the ones investing in these anime in different aspects or when a studio like Toei, Pierrot, A-1, Production IG, Sunrise or any other that are in these almost all the time. Of course, it can and need to be better but the model I think is reasonable considering the funding and everything related and how it's similar to what happen in other industries.
But going in another direction, what would be your idea for those productions without the committee? Who would fund those anime and do what those companies do? Also, without even acknowledging copyright and trademark involved between those companies and adaptations and many other aspects of these productions. There's so much things involved that I'm curious.