Accessing servers without the need to open their ssh port to the public internet. This is the main point for me. Such functionality could be achieved with other means of course but tailscale makes it so easy and reliable that I don't think any other solution can compete with it.

After I install the tailscale client on the server and do some very simple configuration on the tailscale web app to identify the new node I know I'll be able to access it no matter of any firewalls the node may be behind!