For these newer devices, Blackra1n was a tethered exploit. This meant that every time the iPhone ran out of battery or restarted, it would get stuck on a "Connect to iTunes" recovery screen. To boot the phone back into a usable state, the user had to plug it back into a computer and run the Blackra1n exploit again.
Blackra1n allowed users to install Cydia, Icy, and Rock package managers — applications that provided access to tweaks, homebrew applications, the root directory, and the iOS file system. However, the Icy installer was later found to be broken and could cause significant issues, leading many in the community to advise against its use entirely. blackra1n linux
To understand why a native tool doesn't exist, you need to understand the jailbreak process. For these newer devices, Blackra1n was a tethered exploit
During blackra1n's era, Linux users typically had to use alternatives or specific environments: Blackra1n allowed users to install Cydia, Icy, and
Custom rules in the Linux udev subsystem were required to grant the Wine environment direct, unprivileged access to the iPhone's raw USB vendor and product IDs. 2. Open-Source Command Line Alternatives (libimobiledevice)
The best (like RedSn0w) that actually has a Linux port.
When geohot released blackra1n, it relied heavily on specific to communicate with iOS devices in Recovery Mode. Because Apple never released iTunes for Linux, the software couldn't natively "see" the iPhone over USB.