I actually don't think that a toggle would fix the issue, because at least in my opinion - I accept that some people will feel differently - the issue is that a voiced protagonist severely limits dialogue options and makes it harder for the devs to adapt and include new stuff as the process goes on.
As I said, this is largely a question of resource allocation. The current conversation system is pretty great (apart from the conspicuously muted protagonist). But the game shouldn't bog down into becoming a social interaction simulator - at which point voice acting might not be feasible and become the obstacle you see it as. But even then it would be a question of resource allocation.
To give you context as to where I'm coming from on this; I hate text adventures with a passion. This loathing extends to the RPG formulaic dogma of implementing massive amount of written fragmented 'lore' that is largely filler material. If I want to read a book, I'll read a book. Purely written texts in a sea of words is something I most often ignore as not important enough to warrant my time and attention. Your distracting wordiness severely restricts my desire for immersive voices. Tables are easily turned.
As an aside, this dislike of excessive and one-sided 'wordiness' includes the tendency of turning NPC dense areas into 'quest hubs' where you pick up so many quests you truly need a quest log to untangle the mess. Each new such interaction diminishes the previous - blurring everything together. Sometimes less really is more. Will be interesting to see if Larian manages to avoid this trap in their implementation of Baldur's Gate city proper.
