Why can't monkeys speak? Vocal anatomy is not the problem
Monkeys and apes are unable to learn new vocalizations, and for decades it has been widely believed that this inability results from limitations of their vocal anatomy: larynx, tongue and lips. But an international team of scientists has now looked inside monkeys' vocal tracts with x-rays, and found them to be much more flexible than thought before. The study indicates that the limitations that keep nonhuman primates from speaking are in their brains, rather than their vocal anatomy. Ref. Source 2y.
I've often wondered if an uplift project would be worth attempting with some of the more intelligent animals, bring them up to the same level of sapience as us (Not chimps, they're just bastards in too many ways). I think it could be good for us to learn to coexist with other sapient species.
Then I look at all the crap the human species still gets up to, and I realize the uplifted species will probably just end up as segregated slave labor at best.