I do think book prizes are a better-than-average signal but I previously volunteered with a book award. I will caution that pretty much every publisher mass-submits these books for consideration in every remotely relevant prize. It is a cost of doing business (similar to how photographers pay to enter photography competitions to try and win the "award winning photographer" title, or businesses submit dossiers with consideration fees on why they're one of Michigan's top 100 places to work).
There are often so many books and so few willing qualified readers that which books get an award can either be completely arbitrary, or comically easy.
For example, the NCR Book Award in your book corpus faced a big scandal when it was revealed that the judges did not read the books themselves. [1] The PROSE award is so comically large that an ordinary category finalist or win is usually overstated in prestige and value.