I disagree. I’m 45 and proper grammar was a given when I was growing up. My parents and grandparents, who never went to college, all spoke well with few exceptions - even those to whom English was a second language.
We didn’t suddenly have a need for new ways to confuse adjectives and adverbs. We suddenly had an education system that stopped teaching grammar, and the masses were left to fill in that gap piecemeal with whatever words kinda sorta fit because they didn’t know any better.
I’m about to hit 43, while we did proper grammar in proper company in casual conversation we were more with the regular folks. Nobody made “new ways” they’re just the masses ways.
The masses already fill in the gap. Where’d “ain’t” come from? I remember English teachers having fits over it, but we used it anyway, they were clearly teaching us grammar, and we clearly didn’t care. People aren’t filling in gaps piecemeal, they’re talking the way the people around them talk, because that’s the version of the language they understand AND that they know will be understood.