They never really went away.
Many went into hiding, and many, many others are in the refugee camps which are breeding grounds for them, based upon reports I've seen.
At least their "Caliphate" is gone.
Given current laws and the Geneva Convention (which really shouldn't apply to them, since they are a non-state, military force (read "radical terrorists"), and not wearing a recognized uniform for a country they are serving, technically they can be shot, and/or executed on sight, like the Germans wearing US uniforms were during the Battle of the Bulge, when they were caught on the battlefield.
PC-ness will no doubt prevent that from occurring, but short of killing them, I can imagine things will get better, since they don't seem to be the type to easily be reformed, as shown by the statements and actions of many of the Guantanamo jihadis who were eventually released. The very high costs of keeping them in prison is unsustainable, and too many have escaped, or been released over the years, resulting in a very high recidivism rate of the worst kind.
Ummmm, a minor, but factual detail, "the West" did not create the mess in Syria. The guy in charge, the locals, and the Persians did that far before we intervened there, and no doubt have been doing so for many centuries if not millennia.
Libya is another matter, and those that advocated for toppling Khadaffi deserve judgment and scorn, but seem to be getting a free pass from most of the media on their errors in judgment.