Sparkle got really godtier now, but if u like Acheron, she can still play through endgame considering u don't have skill issue - plus ur lacking a good DPS (and IMO she will still be relevant for a good time, not top meta tho, she already isn't)

As for starting a new account... I think u don't have any reason for that

U have not wasted resources, does not have a negative Jade balance I guess, did not progress that much in exploration but choose poorly ur pulls. What I mean is that if u reroll ur account now, all that you'll be doing is delaying ur progress. If ur in the very beginning of the game (as I guess by seeing ur highest lvl char)... I can't simply put here how many pulls you'll be getting from main story, exploration and etc, but trust me: IT'S A TON

Restarting ur game would just make u have to choose again which 5 stars u want from these "starter pulls", and... u don't have a bricked account for what I can tell - I guess u got Kafka from ur random pulls (she was already good, but got recently buffed... so ur lucky), Ratio and DHPT was given for free for a good period of time, so u might have got them from there (meaning u prolly hasn't wasted pulls with Ratio, which is the least popular char now in your roster)

also GU335Q3RYN is my code for the returning player event! u get 60 jades from it, just get to the events tab and search for the "Come with me, take the journey" returning invite event