Villager Breeding is regularly churning out nitwit variants at an extremely disproportionate rate. If I'm not mistaken, the standard rate is roughly 10%, but out of 16 baby villagers, 12 have been nitwits. As far as I know, there's no outside factors that impact the probability of getting a nitwit, so I'm left believing this is some bug in the game's code.
MC-230386
Villager Nitwit Breeding Rates Extremely High
Resolved
Awaiting Response
0
Are you sure this you are on Java Edition 1.17? There is supposed to be a bug where you can't get nitwits from breeding, MC-156556.