This hasn't been my experience at all. There are almost always e-bikes at the Ford stations (per the other comment maybe this was a one off issue) and the Jump bikes work just as well in SF as Seattle in my experience (no shortage of glitches in Seattle).
Jump bikes strongly follow commuter pattern, e.g. if you're going downtown in the morning or back at 5pm, you won't find any but if you're doing the opposite (or midday ride downtown) then, of course, Jump bikes are plenty.
Might be. I experienced no e-bikes for 4 days in a row while I was there just now. I also saw a ton of people using GoBikes during this period, none were e-bikes.
JUMP bikes in SF didn’t work for me most of the time. I would see one, but it wouldn’t let me take it. It worked about maybe 2 out of 6 times I tried. And as I said, the one I just locked with full battery and came back after an hour just wasn’t unlocking without a reasonable error message either. It makes me think there’s a secret reason they don’t let people unlock the bikes (they also don’t show up on the map).