I've analyzed many such websites. Yes, even popular websites like Google, YT, FB doesn't score well. The reason is they don't care about it
For example, Facebook doesn't need any improvement in SEO. They're already in the first position, nothing more to optimize!
In the case of performance, and other variables, it's possible to achieve 100%. But you'll need to remove some functionalities
For example, in my case (in my website), I can remove Hotjar and some 3rd party scripts to achieve 100%. But for me, those are more important than what Google says