There's some parallels to how the consumption of non local media and general connectivity is pushing dialects and vernaculars out of use.

I've also noticed the tool used for communication having a big change on speech patterns too. I basically got the same group of people migrating from IRC, to Discord and then to Signal group and the level of discussion hit rock bottom with the last move. Most of the dialogue shifted to phones and it's inconvenient input system and lack of readability. Even if people return to the desktop the space is already polluted with low quality short-form banter making it less attractive for higher level of communication that used to be the default.