It'll be replaced with a standard share button once navigator.share() API launches.
Is it because "Sharing" in this case us meant to imply pushing the content to another medium (such as an external browser) vs. just the implied meaning of "sharing with another person?"
I'd love any context you can share from internal discussions around how prominent to make that functionality. I think it is hard to deny that Google benefits from it being harder to find, which is where the criticism from the parent is likely coming from.