Im not a sound designer but In 2021 there is no technology <filtering software> that alters one recording of a voice to whatever?? Male / Female / Orc / demon etc....??
Yes, you can process audio to modify timbre and pitch, and probably a number of other characteristics, but the resulting experience is not always comparable with the original quality; that will probably improve over time.
The alternative approach is generating the speech using audio samples from a voice actor. This has the advantage of not requiring pre-recorded audio, but is more challenging to achieve the intended quality, particularly the "colour" and "character" that a voice actor can impart to lines through an understanding of the context.
The flexibility of the latter approach will probably win out in the end, but we may first see games where the voice actor records fixed dialog, and a generation system uses their "voice" for less scripted audio.
"Deepfake"A/V techniques already show the direction of travel.
