I found the ongoing swap format helpful at times, but parts of it can be stressful. I could chose where to send (postage costs) and also a craft or theme within my abilities. I could decide on crafts that were flatter and more lightweight (postage again) that I was certain I could get done and mailed in the set time period for that swap.
It could be a bit stressful if someone claimed that perfect list that ticked all my boxes, but with some waiting and some luck the same list (or another one I liked) would be up again soon. It helped to know that you don’t have to claim anyone. No claims and a chat with the organiser = swap removed. Some months it just might not pan out, and that’s ok.