I always put detergent powder that comes in a plastic pack into a container. Those packs eventually split or spill or the powder starts to cake. In fact the container I currently use came with one of the packs.

Pods sometimes come in plastic packs and some come in a tub. Buy a tub first time and refill with packs. Everything else comes in a handy container.

But I don't like pods. You can't adjust the dose to the load.