In a sense, yes, the engine is too good. If you continue this trend, eventually nobody will have a reason to leave Google because anytime you search for anything Google will have the answer to everything.

Sure, it's convenient but it's also a bit frightening for one company to have that much power and I think that's what people are a little hesitant about.

Google should help the users choose whether to visit the site in question or not, but not flat-out remove the need as everything is directly presented in Google. Often the sentences Google shows in the card excerpts are lacking in context, but you wouldn't know without visiting the site.

This would be comparable to write a scientific paper and only reading the headlines of each source you're using

I’m not sure if you’re being dense on purpose. They are not just excerpt. They are taking full on paragraph of content. We aren’t talking of the meta description here. It’s taking so much content that you don’t need to click anymore. Google is now the encyclopedia, with content they did not create.