As you're asking for feedback: the components are not accessible. I've assessed a lot of UI libraries [1] and most of them have issues. You can start with running Lighthouse (Audit tab in Chrome) to get and fix at least all the tool-detectable issues.
Not a criticism of your project, but could someone give me an idea as to why neobrutalism is popular at the moment? I first noticed this trend on Gumroad's site. It def looked cool, but more sites seem to have adopted this style, so much so it seems like an entire design pattern (sort of like material). It doesn't strike me as "timeless", more like a cool trend.
Brutalism is a architectural style that was particularly popular in the 50s and 60s, characterised by lots of concrete and flat surfaces. See for instance the Boston City Hall or Trellick Tower in London.
Neobrutalist is a term that is being used quite a bit now to refer to user interface designs with a similar aesthetic, that being plain colours and sharp angles.
Congrats on the project, what you did looks nice but I have to say this: “brutalism” and “react” kind of clash in my mind. I understand you’re inspired by the brutalist aesthetics, but I read the very definition of brutalism as “not react”.
Looks great! Not sure if this is a Tailwind thing or not, but I think any presence of hex codes in your examples is a little disappointing. It should be trivial to adjust colors from a fixed palette, rather than find-replacing hex codes across a codebase. Especially for modifier colors like the active tab states.
EDIT: I realize now that this is meant to be copied into an existing codebase, not used as a library, so you are expected to adjust this to your taste.
That's tailwind in a nutshell. If you want to change colors across a code base, you have to find and replace. Now, the colors are "named" using a system, but it's still f&r
Do users like an aesthetic remarkable for it's not blending in anywhere, ease of construction, and lack of polish, or is the predilection towards brutalism a byproduct of the people making it not wanting to put in the care or work to make something fit?
ugly is an aesthetic and it communicates, when intentional, a focus on function or simplicity rather than looks. Now to your point, ugly in anything more than a css stylesheet is a little bit moot as it is an aesthetic that remains superficial and does not inform the implementation but only the consumption.
It would feel more appropriate to me to not have rounded corners at all - you'd be hard pushed to find rounded edges on a truly brutalist block of flats!
I should have mentioned this in readme and docs, but the point of this project is to inspire you to make your own neobrutalism components based on those I created. You can edit them however you like :)
I get you're craking a joke, which made me laugh, but just in case you weren't aware the original meaning of "Brutalism" was from the French word "brut" or "raw". Think raw concrete, not "being brutal to someone".
[1] https://darekkay.com/blog/accessible-ui-frameworks/