> saddened at a future where all this is locked up in corporate hands

I would guess this rolls out from big companies first because the first version is always the most difficult. It’s only going to get easier to do and I would totally expect end-user controlled TTS systems to get better and eventually exceed the capabilities of this version from Apple. Of course Apple isn’t going to sit still, so they will continue to improve as well.

Are there examples from ten or twenty years ago of a technology that big companies had locked up that never made it out to end users? What we have might lag, but it seems like this stuff only ever gets easier to do.