Just a few hundred years ago it was actually possible for a single person to learn essentially everything that was known in Western civilization. And some wealthy people with a lot of leisure time pretty much did that. So now we still see it as a goal to strive for even though it's no longer achievable.

But how many people really try to do that? I’m not aware of any well known true renaissance men/women. Perhaps, perhaps Elon Musk comes close. But even then he’s far too concentrated in tech, just different tech industries. And even short of that, what percentage of people have any kind of cross-training in orthogonal disciplines? Getting an advanced degree in one field is seen as a huge accomplishment. Is society missing out on something due to this? My impression is that ‘way back when,’ everyone who was ‘educated’ had a pretty solid background in history, literature, and philosophy. It was just what you did if you were ‘educated.’ I think much of that tradition is diminished now. Not gone, but diminished.

To some degree, yes, but a lot knowledge can be accurately summarised, and is also both useful in general and even necessary for the good functioning & growth of society. It's not even really about knowledge, it's more about ability - to think critically, to exercise empathy, etc.