The thing for me is, even with fewer lines, I get more connection and personality 99% of the time from the voice acted characters. Also for me, having voice acting only sometimes and not all or none seriously throws me out of the game.
What throws me off immersion is the woman at war maidens asking me of I know about her father every time I see her. It's easier to give her a hundred different things to say if only a portion are recorded.
I'm becoming a fan of the idea of only some of the dialog being recorded. Comments made in passing, shouts in combat, pivotal scenes, yes. But not everything. Reading a good chat bot would feel more real than hearing the same voice bit dozens of times. And it would also allow for more context-sensitive comments. Like if followers could be nice or tough, locations could generate unique comments that would fit the characters without needing voice acting. Example: you have to kill four monsters in a cave, there could be a quip made at the end over who killed more and either being a compliment or an insult based on whether the character is nice or tough.
I love the idea of followers but it gets weird when they are oblivious to everything. Freaking out when I go wolf is fine but other times I do things that should give them pause and they don't even notice.
This is where you have to design the game around the limitations of the technology. Early shooters like Doom never did natural environments because it was impossible to not make them look terrible. Successful cgi movies use cartoon designs because realistic cgi is uncanny valley creepy.