They started with less than a few hundred and now there are 10,000 in captivity. 10,000 is not “essentially annihilated”. That’s not counting the thousands which are actively fighting in small groups in places like Libya. They could reconstitute in a heartbeat left alone.
OK, so Trump has contained them. He has made them essentially a non-issue since Obama who let them be a daily threat to America and her interests.
If they try to come back while Trump is President, I have no doubt Trump will crush them.