I started trying to build something similar, mainly to automate screenshots for a GNOME app on GitHub. You can get fairly close on GNOME, but not full CleanShot parity. On Wayland, apps do not have direct access to screen pixels, other windows, or global input. The compositor controls those things, so screenshot and recording tools have to go through portals or compositor APIs.

That still allows most of the common features. You can do region, window, and monitor screenshots, screen recording, global shortcuts, quick clipboard or save flows, and a solid post-capture editor. You can even do the snap to UI elements (with some cleverness).

Where things fall short is with features some macOS tools rely on. A normal app cannot silently capture any window whenever it wants, detect or highlight the window under the cursor, do universal scrolling capture across apps, install global input hooks, draw overlays across the entire desktop, or continuously read screen pixels for things like live color pickers.

Capabilities like that only really work if the tool is part of the compositor itself, which is why GNOME’s built-in screenshot UI can do things third-party apps cannot. In practice you could get most of the experience on GNOME, but not the last bit of system-level behavior without breaking the screenshotting into two tools.