I think you're onto something! I'm still on-device because I joke that I'm allergic to paper (seriously, I actively dislike the experience of using pen & paper…

I think you're onto something! I'm still on-device because I joke that I'm allergic to paper (seriously, I actively dislike the experience of using pen & paper…just a me thing I guess), but I've basically taken a similar route lately of just having a very small collection of Markdown files and I simply jot stuff down in them, check things off, and then delete bits that aren't relevant. Sync via Dropbox and away you go. Plain text is enormously useful, as it turns out, and the fewer bells & whistles, the better!