Some people get overheated really easily. For those people, a blanket made with super-bulky yarn might be too warm. In that case, a lighter-weight yarn is the right call. Finally, ask yourself how much time you are willing and able to devote to the making process. Keep in mind who will be using it, too.
A jumbo yarn that is loosely spun is not going to be terribly durable. It will also not fare well in the washing machine. In short: just because it’s one of the softest yarns you’ve ever felt doesn’t mean it’s the best yarn for a blanket. Instead, look for a yarn where the strands have been spun together firmly.
Worsted yarn is more durable than single ply or woolen spun yarn because of its construction. Multiple plies spun tightly together are the most durable because each strand lends strength to the others.