Volt Switching out and using the Exp. Share on it from lvl 24 till 36 IS, imo, tons of babying. For the entirety of Chargestone Cave, Route 7, the Celestial Tower, Mistralton Gym and the exploration with Surf Joltik does nothing but leech experience off the rest of the party, essentially wasting a teamslot. It is completely unusable for the 10+ lvls till it evolves into Galvantula. Pokemon in high tier are supposed to not require any babying at all. They hit hard from the moment you catch them till the end of the game- Joltik needs to wait 10+ lvls to even come close to their damage output and speed, while even as Galvantula it's still frail as fuck- in fact, most mid-tier pokes are much better than it.
For instance, i'll compare it to Ducklett, because their stats are alike. They both start off with below average stats, but when they evolve both become amazing, so on paper they look similar. Ducklett is obtainable b4 the Cold storage on similar lvl with the rest of your team and starts with base 60 and 65 STAB attacks. If you look up the trainers list in Serebii or Gamefaqs for the Cold Storage and the 5th gym, you'll notice that at least 75% of their pokes can be hit for supereffective damage from Ducklett. In the Cold Storage you find the Scald TM and at lvl 27 it learns Air Slash. It's also one of the most reliable answers to Excadrill, with Featherdance + Scald beating it 10 times out of 10. It also learns 4 HMs. In short, Ducklett's stats might not be great, but high BP STABs help it not be completely useless till its evolution.
Joltik is available in Chargestone Cave on a significantly lower lvl than the rest of your team, but it only starts off with a base 55 attack as its strongest, whereas the rest of your team most likely have access to base 80+ attacks. There are only 3 pokes in the whole cave weak to Electric, 2 of which Joltik cannot beat (Archen and Tirtouga). In route 7 there are again only 3 pokes weak to Electric, but Simipour and Tranquill outspeed and OHKO Joltik. On the Celestial Tower Joltik can hit most psychics for supereffective damage with X-scizzor, which barely 3HKOs them, while they can easily OHKO back. In the gym, all Flying-types outspeed and OHKO (or 2HKO with the Eviolite) Joltik, who cannot even 4HKO them back. It only evolves by the time you get Surf, and even then it's worthless till you cross all the sea routes and get Thunderbolt. It only learns Cut from HM moves, too. In short, Joltik is a hinderance on any team from the moment it's caught till barely b4 the Twist Mountain.