Yes. Many years ago the "..." menu on each search result had a "Block this domain" button, and you could manage your blocklist from your profile.
I can't find much information about it online, but this page from 2012[1] mentions it was already disabled:
Google also offers a web dashboard for manually blocking spam websites, one URL at a time. You can add up to 500 different websites to your blocked list and Google won’t show pages from any of the included sites provided you are signed in with your Google account. That’s the promise but unfortunately, this solution doesn’t seem to work anymore.
Note that it was not even on the "..." menu (it didn't exist at the time), it was a naked button under every result, reading "Block all example.com results".
Chuck another feature into the pile of "look how far we've regressed".
I'm pretty sure google used to take some action on terms of the form "-SomethingIDontWant" (for example "nice picture -pinterest") which was common on search engine that pre-dated it. IIRC it never entirely threw out all results with the negative term in them, but it at least used the negative term against results when assessing their weighting.
Maybe it still does, but pinterest have done so well at the content saturation and SEO games that even with the negative weighting they drown out more useful results? Either way it is a usability downgrade for Google's image search.
Domain blocking was some 10+ years ago, while "-site:pinterest.com" still works. I simply use Unpinterested, an extension that adds -site:pinterest to every image search on Google and have been happily ever after.
Seriously was this ever possible?
On Twitch we can block a channel or category.
I believe on Twitter you can say "not interested" although it is more obscure what it does.
Google really should have a way of saying "not interested in this website, ever". Plus, wouldn't that be useful data for them?