For personal homelab, I keep it really simple, and I try to think realistically. Which means, using keys with ssh, setting up ufw and keep as little exposure for ports as possible, fail2ban, only really using user accounts with sudo instead of root, use containers and vms when I can to help keep things contained if I am working on something that might have links or files that are malicious, run something like a PiHole or AdGuard Home, etc.

I do plan on adding pfsense + security onion once I can get the proper hardware that has enough ram, but this is probably the only "overkill" I plan on running.

For stuff like VPS usually just UFW + SSH keys is mostly what I need, but add as I needed.

If I ever end up as a Linux Sysadmin, I would use a much more robust and proper setup for the company which means something like grsec, try to do something like setup a much better EDR/SIEM, rotate ssh keys if possible, etc.