I don't understand either, but now power lasers are in the bleeding edge version.
Viewing post in Mindustry Classic comments
that's because there's a new planet and power nodes aren't useful there
Why not? It seems that power nodes would be very useful on Erekir.
you don't have the right resources I guess
Its probably just to add another aspect to how challenging Erikir is, the way gameplay works there is significantly different than on Serpulo, also the erikir power lasers have way more range than the classic ones. Lore wise, what you said would make sense.