That's funny. I perceive resizing windows as easier now, because the cursor change is more dramatic when it gets in the resizing area. Pre-Tahoe, the diagonal one in particular looked almost the same, except with an arrow end in the bottom. Now it splits into two triangles.
I still operate off muscle memory, so it's not actually easier or harder, of course.
Yeah the really misleading part of the screenshots in this article is that it doesn't show the "resize cursor", which basically makes this a non issue.
Also, for anyone reading this who hates the general aesthetic, go into Accessibility and hit "reduce transparency". This has been a desirable setting for last few OSX versions.