The drop rate for cores skyrocketed this season. I've got 6 characters at max and today is the first time all season I've had less than 20 cores. If you're constantly out of them then you're bad at resource management. Sorry to be the one to tell you. Don't get me wrong, I was on team "cores must die" but the problem is solved now. Any infusion I've wanted to make since March has been delayed by glimmer, maybe, and that's an easy solve.