Some examples of the Reddit posts/memes:

https://reddit.com/r/StableDiffusion/comments/1x79gth/why/

https://reddit.com/r/StableDiffusion/comments/1x7ktbu/enshit...

I gave Flux 3 Klein my typical human test that has never failed on newer image models and it did fail; in addition to lower quality, the fingers were definitely not the correct proportions.

Whether the cause is due to more safeguards against NSFW content is hard to confirm technically; it was more an intuition back in the Stable Diffusion XL days but I suspect modern training paradigms are better at correlative inference.