This is the type of question any LLM can explain to perfection on any technical level, from 5 year old to IT pro, so, I'd try that?

If I literally ask an LLM your question it makes beautiful table of pros cons, underlying tech etc. So, LM G<>LLM TFY ;)

Tailscale is most similar to ZeroTier, in that it's a mesh VPN with a control plane to handle key distribution. It's not a virtual ethernet or similar network, so it doesn't do broadcast or multicast traffic like ZeroTier. It does use WireGuard under the hood, and besides the control plane for Wireguard key distribution, you can set ACLs to restrict which mesh participants can connect to which endpoints (on which ports or services), and it can leverage its authentication for some handy tricks like SSH key management.

Most of the neat tricks like funnel, serve, SSH, etc are off by default and you need to specifically allow them for hosts to use them.

TailScale uses WireGuard. Essentially an easy-to-use wrapper with some nice mesh networking capabilities. Quick to spin up. Easy to use.

If you've already installed WG, ZT, and OpenVPN you should know all this, I think.

I've always uses OpenVPN for both business (their Access Server product) and for my own homelab (CloudConnexa). Maybe I'm biased. Been using OpenVPN in one way for over 10 years.