Any particular reason why Willow doesn't just re-ensoul every vamp in Sunnydale?

Maybe for a fanfic, but I think she couldn't have done it in the show. The amount of magic it would take to try and fix every vampire in the town would probably kill her. The bigger spells are exerting for Willow, they drain her (and sometimes physically hurt her if she tries to do too much, like didn't she get a headache and a nosebleed just from doing that spell to transport Glory?) I think it would take too much out of her to even try.
For the purpose of a fanfic there would probably be a way to work around it if anda want to cover that idea, maybe her getting a power boost atau working with a very large coven to share the work? But in the tunjuk I'm pretty sure it would have at least seriously hurt her to even try, not to mention after s6 working with that type of dark magic if she survived it would lebih than likely be Dark Willow who survived not Willow. But in a fanfic there would probably be a way to work around it.

There's also the problem of the orb they need for the spell, is it berkata in the tunjuk if they work lebih than once? It couldn't hold lebih than one soul at a time, so she'd need to do every vampire one sejak one (which might require knowledge of each vampire to send the right souls to the right place) and she may need a different orb for every vampire, and there probably aren't that many that exist. Since I'm pretty sure those orbs hold 1 soul at a time she'd be doing one vamp at a time, and that would take her so long in the time she was doing that lebih soulless Vampires would be getting sired anyway.

I think there probably is a way to work around it for a fic, but you'd need to figure out a solution yu liked to both the power drainage issue and the orb issue.

Well one thing, anda have to have something before anda lose it,right? Well it's the same way with souls,vamps don't have souls, Angel was just cursed with one. So she couldn't re-ensoul a vamp if they never had one. That would be cool if she could though!

no cool tunjuk !!!!!!!!!!!!

Since that curse was only ever shown to be used on Angel, it could have been specifically written to summon his soul and force it into his body. Willow might have needed to alter the spell to summon different souls, and to ensure that they all re-entered the correct bodies. Otherwise the Vampires would have identity crises.

Also, we don't know how every vampire would react to the return of their souls. If they were bad people as humans, they could decide to just give in to their demon impulses. I'd also suspect that a lot would just commit suicide over the guilt of suddenly remembering all they'd done as vampires.

Finally, the idea would only really work as a final episode. Fighting Vampires is such a central part of BTVS. Even though there are other monsters which Buffy and the Scoobies occasionally face, it wouldn't work without evil vampires.