What are you going to do on your phone in the Uber vs on your phone on your couch when you get home vs your phone on Bart? If you have an important in-person meeting to get to then by all means pay the surcharge but let's be real about how some of us are spending those "saved" minutes.
Thank you for doing the math - we're only talking about 23 of them? it's entirely possible to capitalize on 23 minutes, but seriously, 23 minutes?
Can use your laptop in the car safely. A friend of mine had his laptop yanked on BART. Chap ran off, my friend gave chase, and that guy threw away the laptop. Surprisingly, only dented! But I'd rather not experience that. 28 minute ride vs. 45 minute ride after 10 min wait is pretty large difference IMHO. If no traffic, that's even shorter. For me, from Caltrain station (where I live) to airport I have a record door to gate of 16 min. That's a no planning choice. If I have to make a 45 minute ride I have to plan: take the T-line to Powell, switch to BART, ride down to the airport? Crazy. No chance.