By far my favorite keyboard macro tool on MacOS. Great gui interface for making and recording macros. I think it is without a peer on any platform
I am well versed in AutoHotKey for Windows and have written 1000s of lines of macros in it, but Keyboard Maestro makes it so easy to create complex macros for even one time tasks.
Linux is certainly lacking in tools to automate the GUI.
KM is indeed an awesome tool and a must-have part of the productivity combo KM+BTT+KE, though complex macros are unfortunately an area where it falls flat since drag&dropping your way through the GUI to create and refactor complex logic is rather painful
Maybe that's just my limited experience but a lot of Linux software that comes with a GUI like Gimp, Libreoffice or even Isabelle tend to be accompanied by a CLI or API for automating tasks. That may be less accessible than a simple GUI automation but tends to be more powerful.
Though for GUI automation of, e.g., the increasing number of electron-backed apps more accessible software would be nice.
macOS is of course a Unix so it has support for CLI automation as well, and it's pretty common for macOS-exclusive applications to implement it where appropriate (e.g., https://kaleidoscope.app).
It also has several other forms of automation:
1. AppleScript, which often makes it faster to implement powerful scripts than a CLI because AppleScript has objects (e.g., you can iterate through the tasks in OmniFocus for example and use AppleScript's built-in date type to modify them).
2. Automator / Shortcuts, which uses a combination of hard-coded, configurable actions (e.g., an image editor would provide an action to resize an image), and URL-based automation (tell OS to open a URL, URL is sent to a specific app based on a URL scheme, app performs an action).
3. A GUI macro utility like Keyboard Maestro
I point this out because something I see frequently from folks using other OSes is to mention some other approach is better than something unique to the Mac, but macOS usually also supports that other way of doing things. These options are usually additive.
Keyboard Maestro has a CLI too. These aren’t mutually exclusive things, you can have well-designed GUI and well-designed TUI software. I would argue that while Linux has some of the latter (I am absolutely unwilling to give Linux credit for all command-line/text-based applications), it has very, very, very little of the former, largely due to a dev culture that dismisses and diminishes the importance of good design.
To add to the other responses, macOS has had excellent support for a wide variety of Accessibility features/APIs. These same APIs are a boon to GUI automation tools.
Even back in the Classic macOS days of System 7, it was relatively easy to fully automate your GUI applications via AppleScript and Apple Events to allow almost complete unit test coverage.
Note:I have been a server side CLI Linux web dev since the late 90s. While macOS is my preferred desktop, KDE Neon has been my primary GUI for the last few years. There is much I miss from macOS, but I get along with KDE pretty well
I am well versed in AutoHotKey for Windows and have written 1000s of lines of macros in it, but Keyboard Maestro makes it so easy to create complex macros for even one time tasks.
Linux is certainly lacking in tools to automate the GUI.