Hacker News Reader

Craft seems to be build with Catalyst. Apple only introduced it in 10.15. It is technically impossible to support anything below 10.15. Now, it would be possible to write two Craft apps (one iOS and one macOS) instead of a shared one, but that’s much more work and only adds a minority of users (those still below 10.15), so it is understandable they chose not to support it.

Typically being 3 or 4 major versions behind the current version is under %0.5 of the market, it's really not worth it to maintain compatibility that low unless your already old app doesn't need to stop supporting old versions.

I'm estimating because the app is newer, is the reason why they didnt' put special effort in support very old versions like that.

Yes. Obsidian might not yet have an iOS app but it's certainly draw the line of the (real) futur of note taking.