I think I have found an interesting article about it on Wikipedia:
Corporate Memphis is a term used (sometimes disparagingly) to describe
a flat, geometric art style, widely used in Big Tech illustrations in
the late 2010s and early 2020s. It is often considered to be
uninspired and dystopian.
Common motifs are flat human characters in action, with
Because they are neutral.
It would be difficult for any group - race, gender, economic, educational, etc - to claim a company was being biased if they use overall nondescript, clearly merely representational, character illustrations.
No one can scream they are being detrimental to their "group".
Also.. they can be faster and often easier to produce ...