In addition to not running out of a glue joint, thickened epoxy can also span gaps in poorly fitted joints. Not pretty, but strong.

The instructions for gluing plywood scarf joints for my stitch and glue said to use unthickened epoxy to "paint" the pieces to be mated, and then thickened epoxy to connect them. The additional unthickened epoxy was supposed to make a better bond to the wood by soaking in a bit, while the thickened epoxy held it all together. Clamp just enough to hold it together withour squeezing out all the epoxy and starving the joint.