I think they do in certain circumstances. Here’s a recent example of how the pop report was handy for me, even though it was in a mostly trivia-esque way. I’m finishing off my WOTC black star promos. The most expensive promos are 40 and 41, lucky stadium and pokemon center. Given some sleuthing done by E4 members (Estimated Total Supply of WOTC Promo #40 Pokemon Center? - #9 by livindavido), we know that there are only 5,000 - 10,000 copies of this card in existence - and I’m leaning towards the 5k number for reasons I won’t go into for this post.
If you look at the PSA pop report, you can see that only ~540 have been graded - about 10% of all of these cards. That’s useful to know.