I've been a fan of Daft Punk since 2001 so I'm used to seeing arbitrary definitions of "good" and "bad" sampling from people... Also you say that hip hop "at least adds some layers", well yeah, exactly like Daft Punk. And be honest, 90% of boombap hip hop is actually "just a loop", very rare to hear more at least until J Dilla, The Neptunes and others who started adding way more layers, live playing etc.

About Discovery, let's see what is so basic...

Harder Better Faster Stronger: there is a sample, however the rhythm changes and the talkbox are great and completely transform the original mood, ending of course with the great talkbox solo at the end, which is among my favorite things they have done.

Digital Love, well you can't ignore the amount of things they add: the beautiful bridge played on a vintage Wurlitzer keyboard, the vocals, the atmospheric synths and a superb synth solo at the end. Again, they take a small loop and create a completely new mood with many layers and parts added.

Crescendolls, more basic but they still add so much intensity with the production, the little pauses etc. Clearly an example of taking a small loop and doing a lot with it.

Face To Face, coproduced by Todd Edwards, who also sings on it, is a great example of using tens of micro samples to create something completely new.

I only agree for Robot Rock, it is the easiest sampling they have done and anyway the main thing is that the loop is not that good to me, I never listen to it except in the context of Alive 2007. I actually think most of the 3rd album was made while thinking about the future live show, and not with the goal of having polished standalone tracks. It's well known that they did it in a few weeks and didn't give any interviews at the time.