My thesis is that YouTube and Google Search are in an almost perfectly optimized position, where ±5% product quality would not make anyone switch to another service (this is why DDG isn't taking over, for example), but ±10% (or higher, in the + case) is probably around an order of magnitude more difficult to achieve. In other words, no one other than Google can make a better Google.
I'm using DDG a default on my laptop but I end up adding !g in a lot of searches. Google usually finds what DDG doesn't or places it closer to the start of the page.
I mainly keep it as my default because of the "bangs". Which I could configure my browser to do (and did... oh, when did Firefox add that feature? 15 years ago? More?) but setting DDG as my default saves me having to do that. Plus, sometimes, I can get useful ordinary search results without having to look at Google's trashy results page.
Of course products such as yt and search are far from being perfect, but they are still in a commendable state.