oh, I don't worry on Humankind OST. It will mainly be a matter of tastes if we absolutly want to compare. But in term of quantity and quality it will be really good. I don't even know why this point come on the table. They have a really competent composer since endless games and they announced a large ost for HK (era themes, cultures theme, etc...)
For the rest, yeah, it's rather impossible in term of work to have 60 different animations and voiced dialogues. It would be a gigantic work. And to be honest, I am more interessed of having new civilizations, quarters, units, gameplay mechanics, than focus on the leader (again a question of tastes) and it will be a blessing for modders

And having a customized avatar is simply an interessing take to change from the famous leaders trope. (and not just being a civ clone, when some of us wished for having customized avatar in a 4x)
For voiced dialogues, it seems obvious than it will never happen, basically because some languages of ancient cultures are lost. And even in Civ 6, they made some good work for some leaders, but there is really wacky ones too.
For animations, we will be able to chose a set of "behaviour" which change the animations of our avatar, it's a decent idea.