Packify generates. Describe the product and it drafts packaging designs, with a mockup studio for showing them. That is genuinely useful at the stage where nobody has agreed what the box should look like and the alternative is a designer working through concepts by hand.
Pacdora models structure. Dielines, folds, 3D templates for boxes, pouches, cans and labels. Its output is geometry that survives contact with a printer, which is a different kind of correctness from looking good.
What makes them sequential rather than competing is that neither covers the other's end. A generated concept cannot be manufactured, because nothing in it describes how the card folds. A dieline does not tell you what to print on it. Teams that buy one and expect the other end to be covered discover the gap at the point where it is most expensive, which is usually the print quote.
The pricing shapes differ in a way worth planning around too. Packify's free credits are one-time and never refresh, so the free tier is a trial rather than a plan. Pacdora states plainly that it has no free tier at all.