I’ve personally never heard any security professional say that “ssh is too old”. The primary selling point of using Tailscale ssh is that you outsource the challenges of ssh key management to Tailscale. Eg. managing and rotation of thousands of ssh keys in an org.

This comment doesn't make any sense. The products are mostly different categories. One is a VPN replacement and the other is encrypted shell access. Most people use ssh over tailscale. Tailscale does have a "Tailscale SSH" product but it's not that widely used compared to regular ssh over Tailscale.

You use ssh to manage a multi node VPN?