Probably not? I rarely write but there are still times. I have a whiteboard in my living room that is sometimes useful for tracking games or whatever when people are over. When doing woodworking or construction making marks and writing down measurements is very convenient.

I could maybe see these be replaced by AR, but even 50 years seems too short for complete replacement.

I do think cursive will go away. It seems to already becoming very rare. At this point writing large amounts of text by hand is a niche feature and slight speed improvements seem marginally useful. At this point written will largely look like typed text which means that writing will still be easy, you just mirror what you see on the screen rather than learning a separate set of figures. (IDK how this applies to other languages.)