I feel that way about most of the artists mentioned here from the 80's onward. Having grown up with the music / musicians in that IQ challenge, I was familiar with almost everyone except some of the groups in the answers to Question 4. Still, I only got 2 correct answers. There's a lot to know about any era.

I don't think that someone who didn't experience the 60's-early 70's directly would gain significant insights from most of the groups / artists in that quiz. That doesn't mean they aren't good--even a bad artist can give you insights about a musical style or period, just that most of the popular music of the 60's-early 70's isn't particularly iconic. Every era has its share of pleasant but not memorable songs (in fact, most pop is going to be forgotten).

That said, I do recommend familiarizing yourself with the songwriting duos in Question 1 and the proto-punk / garage rock hit "Little Girl."

And here's another recommendation from that period that in my not-so-humble is iconic, though not well known today: Caravan's "If I Could Do It All Over Again...." It covers many styles: pop, prog, rock, even a bit of R&B. If you check it out, try to set aside at least two listens.