@publicvoit You mentioned owning a #Boox eink tablet. So do I and in my case, the OCR works very well (both on German and English). This tells me, that the technology exists. It's just a question of implementing it.
I use two notebooks, one on my desk and a pocket one on the go. Once every few days I go over my notes and add the important stuff to my TiddlyWiki. But I would really like an open source workflow that could handle all notes including digitizing and OCR.