You mean like it's possible to do with cron + rsync? Or maybe something like BackupPC, or Bvckup, depending on whether you also feel like you should automate backups of your own devices, not just a particular file?
> Oh, and put it on a server somewhere if you want to share it with people without needing to email it to them.
Come to think of it, why not have this folder (that's also backed up) be a part of your own Nextcloud install?
> Maybe transform it into HTML+CSS if you want it to look better than the browser default text, and change it a bit for people on mobiles.
Nextcloud handles both the remote storage aspect (e.g. a copy in another location), sync with your devices when you want it both on desktop and mobile, as well as allow sharing stuff through its web UI, if you expose it (or a separate instance of Nextcloud) to the outside world.
> You could also make a form and a service so you can update it when you're not using the one computer the original file is on too.
Curiously enough, they also allow editing many file formats in the browser, should the need arise, so it's not like you need to create that functionality for your specific file/data type when it already exists for text files in generalized form as a part of their software.
> Oh dear, you accidently built your own app.
No i haven't, because while it would be a nice educational pursuit and perhaps just something fun to do over a weekend, i use tools that are better suited for the general use case (preserving and sharing files, optionally with a web interface) and that are actually maintained by others for this.
You don't always have to reinvent the wheel for everything, depending on existing software that's probably both stable and popular (and hence well supported) is entirely valid for this. Text files are perfectly well as the actual storage medium.
Of course, if the OP wants to make an app for this, let them! Nothing wrong with that either, different things will work for different folks. For example, i almost always use LibreOffice for working with documents locally, but others do it almost only online with Google Docs or whatever Microsoft offers nowadays.
That said, i still think that there is perhaps some merit to the critique over micro apps popping up but many of them probably not being viable long term and just being bound to disappear eventually.
