If they have the money for it, a fully voiced pc would be great! With a great voice actor like they got for Shepard!

But they wouldn't have one or two characters to fully voice "like Shepard".
At the bare minimum they would need to do it for EACH "Origin character" that is playable as the protagonist, then for the male and female version of the "generic Tav" and this is IF they decided to ignore all the bitching about the current custom voices not being different enough.
That would make for SEVEN fully voiced protagonists IF they would stick to just five "Origin companions" without adding anyone AND if they would DITCH two of the current custom voice options, rather than adding even more ones as everyone is asking.
Otherwise they could easily become 8, 10 or 12 options for a MC...
This was discussed a dozen times already over the past almost-two-years. Why it has to be explained again?