I can answer this, since we have a Rivian R1T. We had it before the EV9 was announced, but when the EV9 came out and reviews were published, my wife and I were able to talk about it. The Rivian is her vehicle, though, so these are probably her values and priorities.
The EV9 starts at a lower price but the most expensive ones, with AWD and bigger battery pack, is pretty close to an entry level R1S. Going with the R1S gets you a lot more power, and, we think, a better interior that feels nicer. I'm sure the EV9 interior materials is more appropriate for families and children, but we have no children or pet dogs. The base EV9 has something like 200 HP. It does not seem like it would be exciting to drive. All Rivians are exciting to drive.
Regarding R1T vs Lightning, modern pickups are huge. I don't want something the size of an F150, plus the Rivian's interior is much, much nicer. We only use the truck bed occasionally, so while it is small, it's fine. Maybe my wife did choose it as a fashion accessory (I really wanted the SUV) but she specifically wanted a truck bed of some sort instead. We got pre-order pricing years ago, so we got our "cheap". We haven't had to reevaluate value.
Her truck does not have CarPlay. My car does have it. The Rivian UI is pretty good and touch friendly, so it's not too bad it is missing, but doing more complicated things with the phone is annoying. If I'm driving it locally, I make sure my phone is paired and start audio before I depart. If it is on a long road trip, there's someone else in the car to take care of anything more complicated than the completely adequate media controls to pause, play, select next track, etc. My wife gladly trades CarPlay for over 800 HP, a truck bed, >300 miles range, her favorite color paint that's not too common on vehicles, a nice interior, and modern EV tech stuff. When I had a Mini Cooper, CarPlay was much more important since the built-in infotainment was so much worse.
