I also thought the same thing when I was leveling spark. The damage just falls off a cliff early. I don't think leveling as spark is ideal if you're playing lightning.
I am currently testing out other spells for leveling lightning.
I am actually level 43 and using orb of storm + ember fusillade.
It casts faster which triggers orb of storm faster and makes use of the lightning infusion. The single target has also been fantastic.
I saw that you're a sorceress and haven't ascended yet, but you can just skip getting "Sacrificial Blood" notable.
https://poe.ninja/poe2/profile/imphilxd-4709/character/LightningPractice
https://pobb.in/9-hGX2Rjqwlz
edit: Your tree is not ideal, I'd recommend following a guide if you want to continue as spark.
https://mobalytics.gg/poe-2/builds/anthonys-vampire-queen
https://mobalytics.gg/poe-2/builds/animeprincess-stormweaver-sorc-league-starter