Well, Arceus-Electric's pure Electric typing makes it the only Arceus forme that has a good matchup against both Primal Kyogre and most Flying-types. Importantly, this means that Arceus-Electric is one of the few Calm Mind Arceus formes that can muscle past Ho-Oh. Good overall bulk and a Steel resistance also allow it to serve as a solid check to Mega Lucario. While Arceus-Electric competes heavily with Arceus-Ice and Arceus-Rock for a teamslot, these Arceus formes can neither check Mega Lucario nor offensively check both Primal Kyogre and Flying-types, giving it a small niche in Ubers.
However, a weakness to Ground-type moves makes Arceus-Electric extremely vulnerable to both Primal Groudon and Arceus-Ground, which are ubiquitous in Ubers. Arceus-Electric also has issues functioning as a Calm Mind Arceus forme. It cannot run a mono-attacking set with Refresh due to such a set being completely walled by several of the best Pokemon in the tier, which renders it extremely vulnerable to Toxic; unfortunately, Toxic is very common on more defensive teams, which Calm Mind Arceus formes are supposed to be able to beat. These flaws mean that Arceus-Ice and Arceus-Rock are often chosen over Arceus-Electric. Both of these Arceus formes can also offensively check Flying-types yet, crucially, actually function with only one attacking move, allowing them to use Refresh and serve as much more reliable Calm Mind users in general. Do not use Arceus-Electric unless you require its specific qualities, as it is usually outclassed.