The answer was in the fucking title and you still got it wrong!
Sure on a pure production based outlook ebikes would be worse since they require more material.
But e bikes allow people to go further, and encourage people to use them more often, meaning an ebike will replace more car trips than a standard bike would. This can end up offsetting the extra costs of producing the ebike in the first place.
Apparently a fancy lightweight aluminium frame regular bike can be worse in terms of resources used for producing it, compared to a regular ebike with a steel frame. I guess this also counts for titanium and carbon-fiber frames.
I mean, i guess, but there are aluminium, carbon and titanium ebikes too.
I like that ebikes get people out of their cars, and they also get a whole different demographic riding, which in turn - at least i have the hope - will lead to way broader parts of society wanting better infra.