[bobthepanda]

now that e-bikes are so prevalent, I wonder if we will see more regenerative braking.

i live in a place with large hills that have long descents over miles, and it would be nice to not be wearing out my brakes physically while controlling my speed.

[mauvehaus]

To have regenerative braking, you'd need a hub motor or a bottom bracket motor with a fixed hub and the freewheel on the crank, which admittedly does exist, just not in conjunction with a motor in the bottom bracket AFAIK.

You'd also need some way of controlling the regenerative and friction brakes together. No, it cannot be separate levers. A lot of casual cyclists don't use their front brakes because they're worried that they'll go over the bars.