An interesting thought: Could you write an operation/safety manual using current high school english and have anyone understand it? Seriously, I doubt it.
Unfortunately, the high school English curriculum places almost zero emphasis on spelling and grammar.
Whilst I agree that "getting your message across" is important, the reason that we have rules of spelling and grammar is so that we have a standardised means of communicating those ideas. At the moment, there are still enough people who know "standard English" that we understand the relatively small deviations from it. But when people who only know non-standard English teach the next generation, and students introduce more variants, and so on, I am concerned that we'll soon reach a point where the ability to clearly communicate is substantially diminished, and there's very little that's "standard" about English. (Yes, I'm aware that it's already a very diverse language with many inconsistencies and dialects etc; this only underlines the need to preserve what standardisation exists.)
I like to think that I communicate quite clearly, yet I had the option not to do English in Year 12 (SA), and didn't, because it was very much focused on
literature, rather than English
language. (Literature is valuable, too, but it wasn't something I viewed as a practical skill, being a very pragmatic 15 year old.
) I did Accounting instead, because I felt it would maximise my marks. It was a good choice - both in terms of maximising marks, and giving me a practical skill.
And my English skills are stronger than many of my peers who chose Year 12 English.
As more information transfer moves to video and podcast, spelling is likely to become even less important.
I can't see the written word losing its importance. The written word still has huge benefits, particularly in being able to easily change pace while reading. I know when I'm reading, my pace varies constantly. Some sentences I fly through at double speed - "I got it" - and other times I slow right down and go word by word. Yes, to an extent you can do this with video, but nowhere near as easily.
I love online lectures and documentaries... but I nearly always read the transcript rather than watch the video.