It did for me, I can no longer find any GitHub project. Duck duck returns them on first try. Absolutely ridiculous, couldn't believe my eyes when I finally realized that. I get a ton of ads and product placements on first couple pages. What I search for is literally, word for word, name of the repository and it's not ambiguous.

Yes, significantly, but not recently. It can't search anymore. Like literally, it can't. You cannot reach a web page you know exists, like you used to.

Depends what you mean by 'recently', but for me they are much worse than they were several years ago. There was a period when people were complaining and I didn't really see why, but eventually whatever it was caught up with me too. I think it's a combination of losing the battle with SEO spam and prioritising things other than giving me what I actually ask for. There's lots of obvious junk (either 'AI slop' in the truest sense, or the human-written version that was common pre-AI) that finds its way to or near the top of the results; also, it can be difficult and frustrating to convince Google that I'm actually looking for X rather than the superficially similar and more popular Y, and that I would prefer a small number of actually-relevant results to a million irrelevant or sloppy ones.