I work in software, so I guess we use a whiteboard instead of a blackboard. There are tons of options for virtual whiteboards that have features which sound like they'd meet all your needs and more. One big plus is that you can virtually collaborate, which is a big argument for working remotely.

However, given the choice, I'll always pick a physical board to write on. This might sound like a personal preference, but there's some solid reasoning behind it.

You see, when you want to write or draw something, your brain has to do some kind of neuromancy in order to transform that thought into an idea that can be shared with and understood by other humans. When you write physically, the process is very kinetic. The idea starts in the brain, then is sent to the hand to write it out, and is verified by your eyes for correctness.

When you want to write that same thing digitally, there's more steps involved in subtle ways. You have to decide which tool is best, move things around with your mouse, know which keyboard commands will translate to the thing you want to do, etc. Many of these steps are far more abstract than picking up a marker, and for this reason there's a higher cognitive load in transcribing digitally.

Depending on what you're doing, that higher cognitive load can come back to bite you. A lot of my whiteboard time is ultimately spent on reasoning out a complicated system, brainstorming, or trying something new. In these cases, you want your cognitive load to be as low as possible because you want to be able to use it for the task at hand.

However, that's not to say that there isn't a benefit to the digital tools. Collaborating with remote colleagues is difficult without a virtual tool. You also typically benefit from having an infinite canvas, which means your board is always going to be as big as you need it to be. If you already have technical drawings or specifications or whatever you can also easily copy/paste them in.

So all this to say, I guess the way I look at it is that physical and digital boards are separate tools. You want to use the right tool for the job, and in my evaluation the physical boards are still very useful tools.

I'm just guessing, but I assume that after a certain point, what you're trying to draw is so niche and/or new that no one's bothered to make decent software for it. Like, you can do a Feynman diagram quickly on a chalk board, or spend 3x as long dragging lines in Visio or something to make a diagram diagram.

Even with CAD existing, I still always sketch initial project ideas out on paper just cause it's fast and easy.

I had a college professor that hid his artisanal Japanese chalk in a hole in the wall behind the blackboard so that he didn't have to carry it around (and risk breaking it).

I'm not kidding. He said it was his favorite chalk and he bought a bunch of it in Japan.

You use the tool you have. We have the luxury of whiteboards and four or five colours (and even monochrome print), but if you work in a university you may only have blackboards, and perhaps that Japanese artisanal chalk is nicer to use

Anyway you can save any *board work; you have a phone with a camera. I have so many pre-pandemic photos of sprint planning boards in my photos