This might not be a fair argument against this design system, since it was created to combat the inconsistencies between products in the console, and I believe it's doing a good job, perhaps just slower than we'd all like.
Having been in the AWS console on a nearly daily basis for the past 3 years, I've definitely seen some of their screens that are terrible, some services that are hard to use and I've also seen screens get worse/harder to use with design updates even if they're more consistent. Often this is followed by consistent and better functionality, but that varies per service. I definitely understand where you're coming from as it feels like support for any given service in AWS is a game of chance, but the designs are absolutely converging over time.