“but for those of us who grew up in densely populated metropolitan areas, we heard different regional and global accents every day of the week and got used to listening to the content rather than the accent early on in life.”
LOTS of research - and as we can see from this thread alone - many peoples lived experiences disprove this
As pp said certain industries do a LOT of research on this in order to maximise profits by skewing their employee pool in certain ways eg having call centres in places where the local accent is considered by likely customers to be “trustworthy” and “honest”, advertisers choose voice actors for their accent or certain accents they can do because those accents are considered marketable, companies choose the voices they have on their response systems (those most annoying “menus” we all get when we call big companies) based on this research.
It’s not mere chatter on places like mn, it’s a serious area of study with real life application.
Much of our response is subconscious, just as there’s research showing that job and uni applicants with “ethnic” names are less likely to succeed, so are applicants that attend interviews judged on their accent. Again there’s research on this where they’ve used people who can easily imitate different accents.
In the military while no longer officially allowed (supposedly) officer recruits are still ENCOURAGED to lose a “regional” accent if they have one. It’s done in subtle ways where the intention isn’t made overtly clear -
“You need to speak more clearly”
“Enunciate properly”
“Speak more slowly”
But such “encouragement” isn’t given to recruits who have Home Counties or rp accents! Even if their speech is on the sloppy side!