I use zerotier as a way to connect to my private emulated servers without having to worry about connecting to an external IP address and opening up a ton of ports. Plus if you have a dynamic IP, the address can change. Some people set up a domain name to circumvent the dynamic IP, but it still means you have to port forward. Zerotier solves it via creating a manageable virtual lan network. Think Hamachi.
In my use case, I run a solo EverQuest server emulator, WoW server emulator, City of Heroes, Ultima Online. I simply spin up my virtual machine connected to zerotier then boot up my steam deck. Then I can connect to them while I’m out and about at a hotel, friends place, etc.
It’s lightweight, so not much bloat, does exactly what I need it to do and initializes on startup. Then if you want to disconnect/reconnect, it’s really simple to do. Been using it for about a year now. Zero complaints (no pun intended).