Perhaps unrelated, but generally when companies establish monopolies and are valued primarily on their profits rather than their user growth their incentive to build the best possible product will diminish rapidly. For the mega-cap tech companies today their incentives are to add friction to prevent user migration and to aggressively monotonise their existing user base.
This is why today sites like Reddit mostly focused on adding app nag messages to their site and appending posts with distracting badges for additional revenue. It's also why companies like Google don't care about your thoughts when it comes to removing dislikes from YouTube and continue to promote paid search results and their own search content every year.
Usually when the product becomes so bad that people forgot why they use it in the first place a competitor will come along with a user-first approach and disrupt the market, but this is a process that is likely to take decades rather than years or months. In the meantime you can expect Google and other tech monopolies to continue making their products worse from a user's perspective.
I find myself using a mix of search engines these days. Google is still my primary when working (code-related searches still preform better imo), but typically use DuckDuckGo on non-work devices and very occasionally I'll use Yandex when I'm searching for things which might be influenced by political bias.
In the case of this specific question though I'm not sure whether Google consciously changed their search algorithm in a way they knew would result in poorer results. What it might suggest is that Google isn't putting as much resource into optimising the quality of their search results as they have previously. I know in recent years I've found myself increasingly using the "site:" modifier to return results from specific high-quality forums and sites which I trust. I find the vast majority of results for general queries these days link to ad-riddled, low-quality content farms.