Honestly, my main use case for Tailscale is my home lab and being able to access my home network devices using a Zero Trust platform that's fully secure. It has been so useful, especially for sharing some of my self-hosted services with family and friends.
For example, I use Tailscale in my home lab by having it installed on all of my devices, like my personal laptop and PC, as well as on my servers. On my servers themselves, let's say I'm hosting a web page on port 3000. I could just use my Tailscale MagicDNS name and then the port, or I could just use the Tailscale IP and the port to access those web pages. So for example, I host things like VIQUINIA and some other things I can easily access. Another use case that I have for Tailscale in my home lab is I have it installed on my firewall, which is built with OPNsense. What I do is I have it set as an exit node and I also broadcast my entire subnet. So that way, it's as if I'm connecting to a regular VPN and have access to my full home network, not just the devices that have Tailscale installed on them. I can also funnel my traffic through my home network if I'm elsewhere. Since I have my own custom DNS set up, if I am using my network as an exit node, I get free ad-blocking wherever I go.
For my organization, we use Tailscale for our database as a secure way to access our VPC. It's really great. It's an easy way for everyone to connect and disconnect. Nothing clunky, nothing being left behind, very lightweight, very nice UI, and very useful. For my home lab, it has been great because there are services you want to host, but you don't want to expose them to the public network, and using Tailscale gives you a very nice way of actually accessing that without having to deal with exposing things to public ports. I also really appreciate Tailscale services, which I forgot to mention, which involves hosting a service on Tailscale itself.
Regarding metrics, I guess a lot of times it saves hours. Sometimes I forget something at home and if I use Tailscale, I can easily access my network and grab it, whereas usually I would have to drive back home. I feel that in itself is really huge.