But it does actually decrease usability? Useless badges with non-sensical labels or colors without meaning are just confusing. Or the other example from the website: Aligning content is not just to please a designer's eye, it helps users understand which parts of the UI belong together.
I mentioned apart from misalignment and slop text (inc those useless labels), why would a website visitor who doesn't work in tech and who doesn't follow the latest AI developments care whether something uses a gradient or not?
They come to your website with a goal in mind. As long as you make it easy for them to achieve that, it doesn't really matter whether you have elements on your site that are frequently generated by AI.
What's more important is use AI to make your website more accessible.
As long as it doesn't degrade the site's usability, does the general public care about fingernail cards or gradients?
Looks good enough.