pods are about convenience. exactly same reason that i got dishwasher with detergent cartridges and washing machine with build in container for detergent.

but if we talk about powders, they can be very different with different performance. There are commercial powders (for restaurants and such where dishwashers run on very short cycles) that I afraid to put in my dishwasher and there are eco powders that are made from unicorn tears (tried once, they cleaned dirt but leave stains on clear glass). i went through sds of a bunch of them. most of them have same similar basic ingredients, but in different proportions