Why do Americans say bit instead of bitten?

I'm curious to know why Americans often say "bit" instead of "bitten" when referring to the past tense of the verb "to bite." It seems like a common linguistic phenomenon, but I'm unsure of the reasons behind it. Is it due to a historical change in pronunciation or a regional dialect? Could it be a simplification of the language over time, or is there some other factor at play? I'd appreciate it if you could shed some light on this intriguing linguistic quirk.