So, Ive recently gotten back into writing and been thinking about how much more fun it would be to write Outside.

I know it's not what you're looking for but since it's the tools I'm using for the exact same purpose you're mentioning, maybe they're worth suggesting?

There is no copy paste, no edit, no syncing either but depending what you wish to write, you may not need that—I certainly don't, and I even prefer this to more high-tech solutions for my purpose.

• It’s dirt cheap. Less than 30 cents for the Bic (I buy mine in bulk, normal price should be approx. 1.5€), and less than 3 euros for the notebook itself and they both offer at the very least a few weeks worth of writing autonomy. I reckon most countries should have local manufacturers for those tools (less shipping and less waste are always a nice option). Here in France, I like to use the French Bic ballpoint pens and the French Clairefontaine notebooks/papers (it also helps that they’re excellent products)
• It works great under the sun, on the beach, at the pool, or under the rain. Ballpoint ink is waterproof and quality paper (like in this notebook) can work under the rain and it can even be immerged under water. It will buckle but it will be usable (and readable, if one is using a ballpoint or a pencil) after it dried.
• Highly portable. It fits in any pocket (and small bag), and the Bic sits nicely within the spirals so no risk of losing it and I never need to search for it.
• It needs no charging. It needs no software or firmware updates. It has no bugs.
• It works great with any pen you fancy, be it this cheap Bic pen or some multi thousand € fancy fountain pen.
• One can use it to write absolutely anything. Poetry, the next best-seller, a secret plan to conquer the world, a list of errands,... You can also use it to sketch, to mindmap, to outline, and so on.
• It’s not unbreakable but one will need to put in some real effort. Meaning the thing can take a few beatings without any issue. Plus, if it’s too damaged, it’s cheap to replace.
• Thieve appeal? None. Try letting a tablet or a phone, even a cheap old one unsupervised on any table in a public space…
• Privacy? OK, it's not encrypted but at the very least no corporation is spying on my notes, ever. And I'm free to write anything I fancy, without worries.
• Backups? None. I don’t need any since I use for quick notes that I then reuse back at the desk: ideas, dialogues, short descriptions (a few keywords will often do it's rare I need to write complete sentences), or stuff like that. Even stuff I want to write about in my journal (that stays at home) I will simply write a few quick words so when I read them back later one I will remember what it was all about.
• Icing on the cake? Zero distraction. No social, no games, no Notifications to distract me, and no endless settings and tweaks for me to use as an excuse to fool around and to not be writing ;)

I know it’s low-tech and not trendy at all, but it works great and have been doing so for... centuries (for the notebooks in its current form) if not for millennia (handwriting) and has been used by many authors whose work we're still enjoying/admiring to this day.