Fair enough, you can do some sandboxing this way. But SELinux is not a sandboxing tool in the same way bubblewrap or landlock are. It’s a tool that can put gates around your tools until it’s a sandbox, but SELinux as sandboxing is not in the spirit of “tools doing one thing and doing it well”
SELinux and Bubblewrap are two very different technologies. They could get out of each other’s way better, but you cannot “sandbox with SELinux”.
You absolutely can sandbox using SELinux. Red Hat even has a tool called “sandbox” for just that: https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/selinux_users_and_administrators_guide/chap-security-enhanced_linux-securing_programs_using_sandbox
Edit: and Android sandboxing is built heavily around SELinux: https://source.android.com/docs/security/features/selinux
Fair enough, you can do some sandboxing this way. But SELinux is not a sandboxing tool in the same way bubblewrap or landlock are. It’s a tool that can put gates around your tools until it’s a sandbox, but SELinux as sandboxing is not in the spirit of “tools doing one thing and doing it well”