Everyone is vulnerable regardless of age. There absolutely need to be regulations around how these ebikes are allowed to go based on their power output.
Some of these electric bikes are quite speedy - capable of mixing it up with flowing traffic. So classify them as being motorbikes.
If they can't go that fast, or are "assistive only" (require large fraction of rider pedal input up to a set speed) then legislatively they are a "normal bike".
The thing is, we already have the rules around each style of bike. It's just a classification thing.
Many electric bikes are masquerading and hoping no one looks too closely. So, just look closely. And hold actions responsible.
Yes, and people who are slower and more fragile and take longer to heal are more so than others.
and mass!