Like I said that's true for single rider that's fit - but what about having a passenger on, or being driven by kid/older person ?

Ebikes seem like bikes but they let you go way faster than you would with a bio bike - I don't think it's responsible treating them as such and using child seats or allowing anyone to ride them without training/helmets.

Helmets don't do shit in a lot of cases when you get hit by an automobile - especially some lifted truck that is going to smash you square in the chest - which is why infrastructure is far more important than helmet wearing. Cyclists wear helmets in the US much more than in the Netherlands - and die at far higher rates because we have bad cycling infrastructure.

https://usa.streetsblog.org/2016/06/02/why-helmets-arent-the...

It's not a bad idea to wear one in any case in my opinion, but it really is about the infrastructure. Here's the same author of the piece being discussed explaining why he doesn't wear a helmet much:

https://velo.outsideonline.com/2018/11/commentary-why-i-stop...

I'm not disagreeing with that - I'm saying that even with that I still don't think it's responsible to ride around with a kid in a child seat on an ebike. Not judging you for your choice - if you're a responsible and experienced driver I'm sure the risks are way lower.

But it's not something I'd do, or support as a public policy.

A few years ago a coworker was hit by a truck riding in to work. He called me before getting into an ambulance and said he’d miss our 830AM meeting. Later, he had no recollection of that, he must have been in shock.

His helmet was split in two, and it messed up his shoulder pretty badly and needed months of PT, but no neurological damage that could be detected.

This is in Silicon Valley, he had moved from the UK a year or two prior.