Others have clarified, but I’d like to add that security isn’t one thing - it’s done in layers so each layer protects from potential failures in another layer.

This is called The Swiss Cheese Model. of risk mitigation.

If you take a bunch of random slices of Swiss cheese and stack them up, how likely is there to be a single hole that goes though every layer?

Using more layers reduces the risk of “hole alignment”.

Here’s an example model:

So a router that has no open ports, then a mesh VPN (wireguard/Tailscale) to access different services.

That VPN should have rules that only specific ports may be connected to specific hosts.

Hosts are on an isolated network (could be VLANS), with only specific ports permitted into the VLAN via the VPN (service dependent).

Each service and host should use unique names for admin/root, with complex passwords, and preferably 2FA (or in the case of SSH, certs).

Admin/root access should be limited to local devices, and if you want to get really restrictive, specific devices.

In the Enterprise it’s not unusual to have an admin password management system that you have to request an admin password for a specific system, for a specific period of time (which is delivered via a secure mechanism, sometimes in person). This is logged, and when the requested time frame expires the password is changed.

Everyone’s risk model and Swiss cheese layering will fall somewhere on this scale.