You're right, but I think there are some other benefits to doing away with the chain. I have an E-mountain bike and between chain stretch, chain damage, and mud I go through 2 chains per season plus a couple trail-side repairs. Also, no chain means you can optimize pedal speed/torque for each individual rider, and keep it in the ideal range all the time regardless of bike speed. Essentially it offers a much wider power band than gears and a chain. You could also optimize crank length for clearance instead of torque. The front chainring is also a big point of contact on mountain bikes, removing that could improve clearance with the right design. I'd also be interested in the regenerative braking - if I go on an Enduro ride I'm cooking my brakes on much of the downhill, regen could save those and recharge the battery at the same time. Maybe regen could even lead to a smaller battery and save some weight.
Sure there are disadvantages - weight, complexity, efficiency, probably others too. I think with time those will improve though and this just might be a viable setup for certain use cases.
Agreed. That's one of the big benefits of cheap bikes currently - cheap, available parts that work in a wide range of bikes. There's always been proprietary shit though, this particular tech isn't new in that regard.