Every generation is smarter than the previous generation, on average. That’s why they have to recalibrate the SAT tests every generation or so. Other IQ tests are also recalibrated. One possible reason for this phenomenon is that when you know more, it is easier to pass on more to the next generation. Young people learn faster because older people have learned how to pass the knowledge on more efficiently.
I don’t know what “collective brain” means, but certainly the internet has vastly sped up communication and access to knowledge. People are still individuals, though. Their collective efforts keep on pushing the frontiers of knowledge forward, but there still isn’t any direct brain to brain communication, much less shared thinking.
We, as humans, have not been “given” anything. We’ve created it ourselves. Of course some individuals benefit from the inventions of others, but it wasn’t like there was any magic or supernatural entity that “gave” us the internet.
As always, we gain new things and we lose old things. The computer supplants the typewriter. The internet supplants the telephone network (and other networks, as well). The car eliminated the need for the buggy whip. That which is no longer needed or efficient tends to drop out of use, except for a few craftspersons who enjoy doing things in an old-fashioned way.
Our children will be smarter than we are. Perhaps it is a trend that will add up to evolutionary change in a gazillion years (or less). No one can tell. Certainly it is an evolution of culture and knowledge, if not an evolution in human physical structure and capability.
I think the heart of this question is about loss of old ways. What do we lose when various practices no longer become necessary? Is there a value in keeping up old things, such as card readers or readers for other old formats of data? Is it worth knowing how to carve wood or throw a pot? Is it worth keeping typewriters around? Interesting question. Maybe I’ll ask it.