I love ebikes and generally like what Rivian does, but in a very competitive market it's hard to see the appeal of this.
"It features a new pedal-by-wire drivetrain called “DreamRide” developed in-house. The rider pedals a generator, which replenishes the battery,"
So uh, keep peddling?
Yes, the motion->electric->motion circuit is not as efficient as direct pedal but you are explicitly not stranded.
When you’re biking, it’s preferable to pedal in “safe” zones (protected bike lanes, trails etc.) while relying on the battery for eg intersections and when sharing the road with vehicles. With a regular bike you have to pedal harder precisely at these zones which makes it a little scary. You can also pedal on fairly flat ground/use all that energy to climb up a steep hill quickly without pedaling etc.
My government says the trigger (accelerator) is bad and made it illegal.
In usage, however, I feel WAY safer being able to accelerate (from standstill) through intersections. I once had a chain break at an inopportune moment while doing that - scary! Now my rear hub motor means there's no danger anymore.