I think sourcehut's site looks like a cluttered, ugly mess. I'm glad that your opinion is in the minority, because I like that the web has moved far beyond late 90s-early 2000s design.
If I somehow end up on a similar looking website, I'd often close it and move on to the next result on Google.
My brain automatically associate that UI with an archive website that probably hasn't been uploaded since 2005ish.
If you know that your brain is wrong then why aren't you actively trying to teach it not do that association?
The sad thing is there's a lot of modern tech they're using under the hood; which a majority of people will never see or appreciate.
It's like my buddy used to say, "I gave you the capabilities to design a beautiful Ferrari; and you gave me a Toyota Corolla instead."