That's generally how it works with this stuff though. Not everyone who supports an operation participates in things like airstrikes, regardless of capabilities.
You're not going to deal any type of real damage to them by just cutting off things like bank accounts. They're very well entrenched in their "territories". At some point though, someone is going to have to push in on foot, but currently airstrikes are the best way to soften them up for any type of ground attack.
Assad is the, sadly, lesser of two evils here. Hitting ISIS' front lines against Assad, allowing his forces to push the advantage gained by it to start pushing ISIS back may be the best possible way to engage them on the ground without putting any large numbers of coalition troops on the ground.
Couple that with Iran's Qods forces, the Kurds, and a (hopefully) more dedicated Iraq military pushing from Iraq, they may be able to squeeze ISIS like a pimple.
No matter what anyone says though, There will have to be a ground offensive by SOMEONE.