> I am left handed. … When I was a child, writing at length with pencil, the side of my hand sometimes became gray from graphite picked up as my hand rubbed across the page.

Writing with pencil is fine. I prefer it, and its variations in line weight can be quite attractive. Moreover, it can be done without pressing hard and causing cramps: either accept a lighter line weight or use darker graphite.

I agree with you about the gatekeeping. Handwriting is simple but the Internet has fetishized it. Just write a lot: in a notebook, on index cards, on scraps, wherever. And don't think twice about it: in my experience, most of the time what's written has little if any long-term importance and its greatest virtue is rather to trigger the aware mind to release the idea for the mind's more-mysterious parts to then process, combine, and assimilate effortlessly in the background.