But that's talking about Facetime as if it's a product. It's not - it's a feature of iOS, iPadOS and MacOS. Effectively, Facetime isn't free - it's a unlimited use service that is paid for with your initial purchase of your Mac or iOS device and includes a perpetual, transferable license.
I.e. no further innovation is possible?
It is completely voluntary.
You'll find many required open standards in civic engineering and aerospace engineering, and really, any engineering where engineers carry liability. They adapt and change in response to deficiencies discovered.
Your desire to specifically use FaceTime does not make it a monopoly.
What's the difference?
[1] https://www.cryptophone.de . And no, of course not.
The USA simply isn't a leading innovator in this regard.
Hell, even the different cellular carriers fail this definition because you can't use a Verizon sim card to access AT&T.
The Verizon/AT&T comparison is interesting; because it wasn't so long ago that phones were locked to carriers.
Regulation could and should pry open the private networks of large software companies to facilitate healthy competition.
I’d argue not, as long as users can still achieve the same goal in a different way, and it doesn’t worsen their quality of life.
For instance, in this context, the OP’s mother can still do a phone call, or agree to use a different software - which, by the way, is probably free.
/shudder