Why did this become such a difficult feature to find?

[Papamalo]

The ability to operate totally hands from, from waking up a locked screen to using voice commands was a feature easily found on several older phone, early models of OnePlus, Motorola, Samsung, and others.
Now, among these latest phones, this function seems to be a rarity. I Imagine it would have been simple to leave this function intact in later builds. I just can't figure out why they didn't. Any ideas?

Thanks.

 

[Mikestony]

Security reasons I would guess.