I must say this pisses me off too (and I have an eBike). If they come up fast but slow down until you have seen them and then safely pass, I have no issue. But flying past at speed does tend to take one by surprise and can cause one to go off line, which could lead to a fall.
If I am on the eBike and it is busy, I adjust the power to the point where my effort and speed is similar to the majority of the bikes going up. That way we all ride to the top safely and enjoy the climb.
I am not sure what the other eBikers think when the fly past me grinding up the hill. Probably assume it is broken (as I ride the brand that is rumoured to be unreliable) 😉😂