Apple's stuff is probably orders of magnitude more reliable, the system they use has been battle-tested for decades.

Both Starlink's sat-cells and Apple's Globalstar link will be a real benefit for people who get stuck in a bad situation unprepared, but if I were a serious rock climber or similar, I'd still prefer a full-scale Globalstar, Iridium terminal or EPIRB device, then an iPhone with Globalstar, and only then Starlink's offer.

I think they’ll def come up with a paid plan for extra features. Same way T-Mobile only basic features are going to be free. Same way Starlink residential is orders of magnitude cheaper than marine edition.

TMobile/SpaceX proposed service does sound better than the one Apple currently provides. Apple's works right now though and T/S's doesn't which is a notable difference. I also haven't read anything about the T/S service that says they will exclude iPhones. As an iPhone user, I would love to have access to both services! It's unlikely I would switch to a different phone manufacturer to get access to this service if it isn't available to iphones, but i might switch to TMobile from my current mvno to get it on iphone.