A layered defense is always best. Nothing is 100%, but knowing your threat model will help define how far you have to go and how many layers you want in the way. Defending against State level actors looks different than swatting the constant low effort bot traffic. You’re right, if a bad actor gets root on your machine, all security is forfeit. The goal is to minimize that possibility by keeping applications and packages updated and only allowing necessary connections to the machine. You mentioned wireguard or tail scale. Set that up first. Then set up the host firewall to only allow outbound traffic onto the VPN to the required ports and endpoints on the LAN. If the VPS isn’t hosting any public facing services, disable all traffic except the VPN connection from and to the public Internet both on the cloud provider’s firewall and the host firewall. If it is hosting publicly accessible services then use tools like fail2ban and crowdsec to identify and block problem IPs.

Firewall rules on outbound traffic from the VPS to the LAN would do it. Allow traffic to the hosts and ports that the VPS needs to reach and block everything else.

That’s true, from a certain point of view. What they actually did was give everyone a common target. We still get everything compressed and limited into a flat line, just now we don’t have to adjust the volume on our stereo between songs.

I tell my kids, never start it, but if someone hits you, hit them back hard enough that they won’t want to do it again. I feel like this works all the way up to state level doctrine.