It is a limited resource we dig out of the ground in countries we don't want to be depending on, because to do it in our own countries is too dirty for us. Then we use this bound energy and convert it into heat we release into the atmosphere. The only thing missing for being technically "fossil" is that it's originated from organic matter.

Short from that, it definitively classifies as not renewable, not sustainable, dangerous, not climate neutral, expensive, antquiated idea. And in the sense of being an antiquated idea at least, it is "still fossil".