The other way around. Tailscale cloned zerotier, but they diverged quite a bit. You can find VPN connected hardware with zerotier if you've got such needs, and that's simply not possible with tailscale.
Also, ZeroTier is layer 2, whereas Tailscale is layer 3. So you can bridge your LAN to ZeroTier at layer 2. https://docs.zerotier.com/bridging/
ZT came first
which like, they're open source, so hosting your own is totally possible