- distraction free (except doodling)
- lower power consumption
- expressive in a way that typing can never be
- tends to discourage editing as you write
edit: and less eye strain
Unfortunately the above is easially to say, but hard to force. If you are creating something you should stop if the facts are wrong (no point in continuing when you suddenly realize your argument depends on something that might be false) even though fact check is an editing process. You cannot refer to data in a chart until you create the chart. For many people a misspelling is something their brain will not ignore even though they know the word they mean and fixing it belongs to editing - your flow is already interrupted either way and not fixing it means the flow stays interrupted.
Sometimes slowing down the process like this is helpful, in other cases it's better to make the emission of the words onto the page as immediate as possible, depends on the piece.
You may want to look into writing with your arm instead of your hand
I spent my first few decades trying to train myself not to write in a way that causes physical pain. The closest I got was when I discover Lamy Safari pens, which won’t let me hold them the “wrong” way. That only makes it a little less horrid.
Try a fountain pen. Seriously. Many people press far too hard with ballpoints; with a fountain pen, you can't -- you'll bend the nib and smudge.
Some adults won't have written with one since school; younger ones, never. But they exist for goods solid ergonomic reasons.
After you get used to them you write better, too.
There are good disposable fountain pens now, and I've been using them for a decade and a half. I like the Pilot V-Pen.
https://macchiatoman.com/blog/2020/1/22/pen-review-pilot-v-p...
https://www.amazon.co.uk/Pilot-Pen-Disposable-Fountain-Black...
Costs about £5, lasts many months of heavy use -- much more than any cartridge pen as the whole barrel is full of ink -- and I have never ever had one leak in my bag or pocket.
Highly recommended.