They are only comparing two groups of people who already got sick.
Try exposing 1000 vaxed and 1000 unvaxed to Covid and then compare numbers.
Those numbers would be convincing to anyone.
Thats not a good comparison as the vaxed/unvaxed sets would differ, as the vax has been applied very disproportionately to the elderly. Two such sets with the same median age would work.