I use heavily for keyboard customization. I have all sorts of macros, like moving windows to different parts of the monitor (e.g. left, right, center, top center for video calls), making keyboard navigation more similar across Linux and Mac, launching and positioning apps with a single keystroke, auto-entering common data on a website, and so on.

And there's tons of other use cases (which I don't use), including gestures, controlling gestures, trackpads, MIDI settings, Elgato StreamDeck, and more.

My number one use is a three finger swipe up/down to change tabs in the browser, terminal, IDE, etc. BTT also includes a window manager that lets you drag apps to an edge to half-screen them or snap them to other window edges. It also allows you to create a custom notch bar or custom touch bar, along with many other little tools. I'd buy it again in a heartbeat.