This is why I deleted Fig (https://fig.io/) right after installing it. It must've sent some uninstall information, too, because the creator/CEO emailed asking why I uninstalled it afterwards...
Their getting started instructions [0] are all just terminal commands too, and even that doesn't mention Mac once.
Not that it is not annoying, it is, but that's pretty common with Mac-only software in my experience.
On the rare occasion it is truly just win, it's usually made clear far more than macos only.