I think I belong to the generation that grew up using just Google so I cannot comment on quantification.
The biggest difference for me is that on Kagi, the first results are always relevant instead of clutter/ads that you see on Google.
The biggest difference for me is that on Kagi, the first results are always relevant instead of clutter/ads that you see on Google.
Google represented a huge step up in search result quality generally. But in recent years, the quality has really slid – even while tuning results using more advanced Google features.
I don't think Google cares much about search result quality these days, except insofar as they have to keep a minimum threshold just to drive their ad and analytics revenue.
There is a lot of opportunity for other search engines to make strides forward in quality relative to Google these days.
Another is that they tried to get too helpful and it backfired. There used to be a bunch of search operators that you could use to be specific and most of them don't work anymore. Because that was too complicated for most people. So now instead Google just ignores what you searched for and tries to guess what you actually meant, and ends up showing a lot of irrelevant results, some of which don't match what you searched for at all.
The third is that nowadays almost always, Google tries to spin it into a commercial request. The top results are usually for e-commerce sites or something selling products or services, no matter what you search for. It always assumes you're trying to buy something, not trying to find information.
I switched to duckduckgo years ago, and it generally gives much better results, but even it seems to be slipping a bit now. Still way better than the modernized Google, but for how long?