It is surprising how many times I see this content (this version might be marked “Published: Jun 19, 2026” but I've definitely seen those exact diagrams before, starting at least a few years ago, and the same content around them in many tutorials before that) without it being updated to mention jump-hosts.

Support was added to OpenSSH about a decade ago? Even on a low moving Linux distro like Debian/LTS everyone should have support by now.