Female's perspective here: I have a S with key fobs and just test drove a Y overnight with a key card.
I didn't have the app set up for the Y, so I can't comment on connectivity issues. However, I use a Pop wallet on my phone, so I'd just keep it in there and there would be no issues either way. So if a concern is carrying a card on top of everything else, that's one solution (but a key fob would be extra too)
However.... I will say that I use my key fob 99% more than the app. I use the app to preheat some mornings, that's about it. The key fob is just very convenient. I use a small S clip and keep it in my pocket hooked on my belt loop. Couple things:
- When I walk up to the car the handles extend (although irrelevant for the Y) and unlocks the car (I think the app unlocks the Y at walk up? Not sure) No need to do anything but just walk up. If the app does this, then you'd have to have your phone on you when walking up, which may be the case most time, but it's surprising how often I find myself walking up to it with just a key fob.
- I open the frunk and trunk while walking up by simply pressing the button in my pocket (with the way I have the S clip hooked to my belt loop, I know the button closest to the loop is the trunk, opposite frunk) When I test drove the Y, I found myself looking for that key fob multiple times to open the trunk prior to getting near it, and I quickly learned how not having it would be an inconvenience. Hands were full to where app wouldn't have been useful, but pressing the button would have been possible even with hands full.
This is coming from someone who uses tech/automation/apps for everything, which appears to be opposite of your wife as she's a "non-tech" person as you state, and I'd prefer a key fob. Is it worth $150 for that … that I can't say. I'm not sure I'd spend $150 for it once I get my Y and just get used to not using it.