1974 Kellogg's PSA Grading Update - A Comparison to Two Years Ago

I still have yet to send a card to PSA, Kellogg's or otherwise.  It doesn't look like I will be doing that anytime soon.  

 Here is a breakdown of 10s from PSA from a post I did on 11/27/19.

#10s for a card        #cards in the set that fall into that range

10-19                       3    Monday (#02), Fisk (#05), Santo (#07)
20-29                       3    Gibson (#01),  Coleman (#03), Ryan (#08)
30-39                       4    Campaneris (#04), Luzinski (#09), Otis (#17), Allen (#33)
40-49                       6
50-59                      12
60-69                       5     Palmer (#06)
70-79                       3
80-89                       5
90-99                       4
100+                        9

Of the 54 cards, 12 different ones have had 50-59 10s.  All of the other stars in the set have more 10s than Palmer except Blyleven who has the same number - 64. 

Here is the update as of today - 12/03/21.

#10s for a card        #cards in the set that fall into that range

10-19                       3    
20-29                       3    
30-39                       3    
40-49                       7
50-59                      11
60-69                       5    
70-79                       4
80-89                       5
90-99                       4
100+                        9

Not much change in two years.  Is it because (a) PSA still has a monster backlog, (b) no one is submitting Kellogg's cards or (c) both?  I don't know the new pricing structure, but not many Kellogg's cards will be sent going forward with the last structure I heard about.

SGC hasn't had much grading other than the biggest stars.  I'm not sure about BGS because I am not a member.  I don't know much about CSG or any other players in the market.