Yeah, I can't stand these influencer-wannabe web-devs misusing terms.
béton brut means "raw concrete" in French, and in architecture that's what brutalism is. I'd say only sites that look like they use the default style of HTML with no CSS on Netscape 1.x could be called "brutalist"...
E.g. https://stallman.org
IMO the design is more "Windows 3.1 Hot Dog Stand Theme" https://blog.codinghorror.com/a-tribute-to-the-windows-31-ho... combined with MS WordArt...
Right, hence why it's called "Neo-brutalist" and not "brutalist". It's not just plain un-styled html.
FWIW, from the OP website:
> Neobrutalism is a mix of regular brutalism in web design and more modern typography, illustration, and animation standards. Neobrutalism refuses the usual components of UX-UI design and embraces uncomfortable design elements, and it is more fearless to use distinctive color palettes.