[Gibbon1]

I read a paper some people wrote on the subject. Take away is battery powered pumps can be built as big, or importantly as small as you want. Turbo pumps on the other hand don't scale down well very well. Batteries win at the size of the electron rocket.

I would not be surprised if someone starts work on a larger electric rocket engine because the difference in efficiency is not huge. But however electric is a far simpler and potentially more reliable design. If electrics are super reliable the difference in insurance costs might tip things in their favor[1].

[1] Trade 1:10 chance of losing your sat vs a 1:50 chance for 25% higher launch costs? There are companies that would readily take the latter option.