Culture has been rapidly regressing to a mean long before AI.

See e.g. modern cars. Until the mid 00s, you could tell different brands apart from far away. And you could perhaps also tell a few things about the owner from the color.

Or movies. The past 20+ years of high-budget film-making has been mostly rehashing franchises and remaking what has already been made.

AI is perhaps accelerating the trend and eliminating many opportunities to witness something original (e.g. a quirky amateur wedding video). But the trend had already begun.