I think the most important thing I learned about these cuts from seeing hundreds of people try on cuts like the PBJ 019, SDA 08 cuts, 3sixteen NT, and other similar is that it allows people across all sizes to get a jean that's comfortable w/o losing the desired amount of taper. It also allows those people who want a super slim fit who may not have very slim legs for their size get a slim look w/o having to squeeze into the more traditional slim tapered that were super common 5-8 years ago like the FH 3002, Strike gold 09 cuts, etc. That combined with most brands offering jeans in slightly shorter inseams (33-34 as opposed to 36"+), it makes the jeans easier to fit.
Kyle, you're definitely right that this works very well for people who are on the larger end of the sizes but we sell an almost equal amount of jeans to people roughly my size too who have bigger legs compared to the rest of their bodies (although these days my upper body is catching up).
Obviously fit is subjective and I personally like more moderately tapered or wider straight cuts but from what I've seen, if you're looking for a slim fit and you dont size down aggressively, I dont think the jeans look weird/silly. At least with our customers, I also dont hear as many people complain about not getting their feet through if they listen to our advice to not size down so much.
It's funny seeing how different forums are. you go onto reddit and the discussion for the most part would be opposite...people dont understand how a leg opening bigger than 7.5 makes sense. Even there, I think we'll see a big shift to more relaxed cuts in the next couple years and then it'll cycle back again like it always does.