There are plenty of Electric-type Pokemon that can hold their own in the series, but there are a few that are quite underwhelming.
The likes of Jolteon, Zapdos, and Toxtricity are some of the strongest Pokemon in existence that just happen to be Electric-type. Across the different Generations, Electric-types have proven to be more than formidable.
In Johto, the second round of Electric-type Pokemon were introduced to the series. Not all of them exude the power of those that came before or after. Underwhelming by their levels or status is the right way to describe them.
Note: This article is subjective and reflects the opinion of the writer.
3 most underwhelming Electric Pokemon from Johto
#3 - Mareep
Mareep's final form is Ampharos. Ampharos is an absolute unit of an Electric-type Pokemon. Yes, Mareep is the first in a line of three, but it is pretty weak considering. Pokemon with such a strong evolution should be incredibly strong as well.
The only exception to that rule should be Magikarp and Feebas. Thankfully, Mareep evolves into Flaaffy pretty early, at level 15, and then into Ampharos at level 30. Obtaining the stronger final evolution doesn't take long.
#2 - Lanturn
Lanturn has really great base HP. Other than that, it doesn't have the greatest stats for a fully evolved Electric-type Pokemon. Its Water/Electric-typing gives it access to a great variety of moves, but it may struggle in using those moves.
Lanturn is also weak to Ground and Grass, two very common attack types found in the series. With pretty low Speed, it may not be able to attack before being taken out. That's a shame for such a neat and unique creature.
#1 - Elekid
Baby Pokemon are either loved or hated. There really isn't an in between. In the Gold and Silver games, Elekid could only be obtained by breeding an Electabuzz. That is fine in order to complete the Pokedex.
Otherwise, Elekid is pointless in Johto. Electabuzz can be found on Route 10 in Kanto in Generation II and taken back to Johto with the two regions being found in those games. It is much better to just have and use a caught Electabuzz than worry about leveling up an Elekid.