Joe Scotch wrote:

So it's not clear in their words that they also "share" your IP address
(which I had assumed they did, all along).

They don't have your IP address to share or not share it. They didn't
create it. They don't manage it. They don't care what is your IP
address. Their app isn't what negotiates your OS with a DHCP server to
obtain a dynamic IP address nor is their app involved in the OS
configuration for a static IP address. They cannot share what they
never created, don't manage, and don't care about. Their app is not
involved at the network level.

Their app operates at the Application level issuing system API calls to
perform high-level networking functions. In the 4-layer DARPA
networking model, their app operates at the Application level, not at
the Transport, Internet, or Network Interface levels. In the 7-layer
OSI networking model, the lowest their app might be involved is at the
Presentation level (not a user-visible GUI but charset encoding,
encryption, etc regarding the data construction) but most likely is
involved only at the Application level. The OS and its support libs
handle the networking. The app isn't involved in all that.

https://technet.microsoft.com/en-us/.../cc958821.aspx
https://en.wikipedia.org/wiki/OSI_model

https://www.pcmag.com/article2/0,2817,2307006,00.asp
https://www.pcmag.com/article2/0,2817,2307007,00.asp