This is exactly your problem right here. WEIGHING THINGS correctly. ISIS may lose 50 assets, but they have tens or hundreds of thousands of others to draw from. Its not like each thing they lose is a crippling blow. Its a CONSTANT FLUX of MILLIONS of moving parts. They have been trending UP very quickly until perhaps very very recently, but are likely still seeing a net gain from their activities even if not on the map itself.
Again their tactics are brutal. They put extreme taxes on random things or kill for the multi purpose of spreading fear to make people convert, gaining assets, not having to feed mouths and waste assets on nonconformers. They will (and have been) suck their regions dry for their own purposes first and foremost.
Its amazing to me that I feel compelled to put this much time into this issue. Its just mind boggling to me how some can be so cavilier with such an EXTREME REAL LIFE situation with massive human consequences.
But hey, ISIS is nothing and the revalue is any day now!! HI5!!!