Watching / listening to American media from 50+ years ago, some of the mainstream accents of that time are now completely dead as far as I can tell. Or at leas

Watching / listening to American media from 50+ years ago, some of the mainstream accents of that time are now completely dead as far as I can tell. Or at least, I never hear people using those accents in any context today. (And not just the “transatlantic accent”, which seems especially affected, but others I can’t place/name. I dunno, maybe those are just some non-obvious blend of regional accents.) There’s enough variation in “General American” English, and enough change over time, that I imagine people 100 years from now will readily recognize an “early 21st century” accent.