I imagine periodically making backups and/or using Git could prevent this, no?
I understand with some syncing methods, such as Syncthing, conflicts can be more common.
I'm going for a different approach. All my docs are stored as Markdown in iCloud, and I use iA Writer to edit them. It's a proprietary app, but one with an exception track record of "buy once, use forever". It's a native app, too, unlike a lot of the alternatives. And if iA Writer ever explodes, all my files are right there in glorious plaintext. I could do, and have done, the same with Obsidian, but I just like using Writer more.
The only database-backed app I've ever completely trusted is Drafts. Yes, my data is stored in its proprietary system. However, it exports the data regularly to a JSON backup file that's trivially easy to parse. It's also never, not once, ever, lost a single byte I've put in it. That little app's bulletproof.