I can't think of any awesome software that only runs on Linux. I can think of a couple examples of not-awesome software (systemd and wayland come to mind). What do you have in mind?
If you qualify "running" to mean "I can run that executable somehow" then sure. I can use virtual machines and emulation to run anything anywhere.
If you qualify "running" to mean "runs well in an environment the developers will support", there is a lot of software that is only available for Linux.
Edit: Maybe WireGuard? But that's kind of niche.