Digital is better, and getting better all the time.
I think there was an article somewhere on the web about students lose lesson retention when they're just typing away to capture class notes. Their brain is in "off mode" while transcribing from their ear to their keyboards. However, when a student scribbles on a notebook, they listen intently and find keywords to write down. They are already pre-processing what is important before writing it down. I've had this happen to me. I'm just mindlessly trying to capture everything the lecturer says verbatim. But when I use paper, I'll transcribe what I value as important at the time of the talk and can summarize it fairly accurately.
Perhaps an app like Notability or Goodnotes would be helpful for capturing notes straight to digital. I haven't tried it because I don't have much use for an Apple Pencil for my iPad Pro. But that might be worth a shot. My handwriting is too messy for any OCR to actually read my chicken scratch writing. I also haven't quite gotten used to the idea of writing on slick glass when I've been writing on paper my whole life.
If I'm brainstorming, I'll just go straight to my mind map to capture thoughts directly. But if I'm taking notes during a meeting or class, I'll take out my BuJo.
It is of course easy to lose a paper notebook too, no question about it.
I've taken to the habit of taking a snapshot of important notes that I want to archive. Then I can either put the original paper in a file folder (for official documents like tax papers) or toss it (this week's grocery list). If I lose that sheet of paper, I'm not worried. It's in my camera roll.
Paper is only workable for a very short time and results in huge frustrations and wasted effort, at least for me.
Paper has been mostly short-term storage for me. Everything will eventually get captured into digital for archival/historical purposes. It's easier to do a find query for certain keywords when I'm searching for something I completed or recorded. But paper is worth it for me in the short run. It's flexible enough for my short term needs. My idea of short term is 7 days. I have my BuJo which contains this week's pre-planned work (3 Big rocks and 5-10 single next actions).
I'm not the kind of person who likes to see a bookshelf full of old notebooks. My old boss still has Franklin-Covey planner archives dating back to the early 1990's. He's never referred to any of them because he never had the need to. I don't know how he would go about looking for a specific task or project in those binders.
There was a pain side to this as for every task I put on my daily list was something I committed to in writing. At the end of the day, as I had to transfer my incomplete tasks forward. This forced to acknowledge that I over-committed.
I stopped using a 2-page daily spread because I always had to forward incomplete tasks to the next day. I've decided to look at my work in a 1 week span. Nowadays, I use a 2-page weekly spread. My left page holds my 7-day calendar. All of my due dates, appointments, and other time blocks are held here. The top one-third of the right page holds my 3 Big Rocks and the next 3-5 next actions in them. The middle one-third of the right page has my 5-10 single next actions that I have planned for this week. The bottom one-third of the right page is empty and acts as an inbox for new tasks or notes.
When I do an end-of-day review, I'll choose either a Big Rock or a handful of single next actions and put that in tomorrow's day block. That becomes my plan. I try not to over-commit. Using the weekly spread allows me to see the next few days as well as pre-plan my work for the next day.
If I get a new task from voice mail, walk-in customers, or just life events that come up during the day, I'll put them in one of two places. If it's something that needs to be done this week, I'll go ahead and put it into a day block on the left page (finish Joey's sign project by Friday). If the new request is something that can be done next week or later, I'll go ahead and put it into my digital task manager for future review. Short term tasks (needs to be taken care of this week) will go into the short-term BuJo. Anything that doesn't need my attention this week will go straight to digital.