Yeah Amazon's ML offerings performed very poorly the last time I tried them out. Kendra returned miserable results, and AWS Comprehend had a crappy (very limited) API, multiple serious bugs (like whole-sale truncating input text segments in the response, not handling quotes consistently, etc.) that they took months to fix when we reported them, and never inspired huge amounts of confidence.

In all honesty, I'm not too surprised; my understanding is that AWS has a habit of grabbing open-source projects that kinda/sorta do what they need and build off of that internally, so you're not typically going to be exposed to unparalleled brilliance with their offerings. Mostly it will "kind of" work. But not much more than that.

(I wouldn't say I hate AWS because they do a reasonable job on several points, but they're no silver bullet across the board.)