One more tool targeting OSX only. That platform is overserved with desktop agents already while others are underserved, especially Linux.

Fair point that Linux is underserved.

My own view is that the bigger long-term opportunity is actually Windows, simply because more desktop software and more professional workflows still live there. macOS-first here is mostly an implementation / iteration choice, not the thesis.

That's mostly because Mac OS users make tools that solve their problems and Linux users go online to complain that no one has solved their problem but that if they did they'd want it to be free.