There's are two serious differences between 40 years ago and now.
1) I can look up a thing I can't remember (or don't know) both specifically and immediately. 40 years ago this might have taken a week and an inter-library loan. I'd certainly be sure to remember what I'd learned afterwards. And,
2) Things that I once looked up can be silently changed or removed the next time I try to look them up.
I don't think it's useful to handwave the material differences away with a general "People always say stuff about everything."
Why is it important to remember everything that you've read especially in this day and age? 90% of stuff you Google is just to help you get a small task done or learn something that seemed important in the moment. Another 9% might be something you write down in a notebook to look back at later. Very few things are worth actively keeping track of in your mind and those are usually fundamental building blocks of a new mental model.
An observation I used to see with more frequency, is that a part of thinking depends on noticing patterns and connections between things. If you don't have any working or long-terms storage, this is impossible. Developing new insights will depend on internalizing at least some amount of information.
The googling to complete some small task (e.g. what was the second parameter's type?) -- I'm not sure I'd really consider that thinking, per se. It is definitely something that contributes to our general cognitive load, and the ubiquity of search surely is a welcome aid, as you suggest; there really are too many unimportant things to keep in our heads.
I suppose you could say that it's not useless, but it's use is subsidiary to the primary purpose of thinking, because it is thinking that actually solves problems.
This isn't necessarily true however, on a group selective level, remembering allows you to more effectively pass information to future generations, allowing your community to continue to adapt socially to your environment.
Sheep do this, with young sheep being explicitly taught how to handle a landscape by their parents, which is normally understood as showing them how to walk etc. but extends all the way to navigation and safe routes at least.
In our context that connection is far more obvious, even if that purpose has been in many ways assumed by tools; even if your brain remembers things solely for the purpose of thinking, it may not be for your thinking, and so we can say that memory, on an individual level, has a separate function.
1) I can look up a thing I can't remember (or don't know) both specifically and immediately. 40 years ago this might have taken a week and an inter-library loan. I'd certainly be sure to remember what I'd learned afterwards. And,
2) Things that I once looked up can be silently changed or removed the next time I try to look them up.
I don't think it's useful to handwave the material differences away with a general "People always say stuff about everything."