Help me understand a historical period when this was ever the case.

Social historians have been debunking the thought-terminating cliche that we ever had a trend of merit-based hiring since time immemorial:

https://thereader.mitpress.mit.edu/the-myth-of-meritocracy-r...

https://archive.org/details/meritocracymyth0000mcna_n6g9

https://historicalstudiesineducation.ca/index.php/edu_hse-rh...