OK, but how do you solve the problem? Trusting an image is not so different than downloading a random deb and installing it, which maybe configures a systemd unit as well. If not containers you still have to run the application somehow.
Ultimately my point is that containers allow you to do things securely, exactly like other tools. You don’t even have to trust the image, you can build your own. In fact, almost every tool I add to my lab, I end up opening a PR for a hardened image and a tighter helm chart.
In any case, I would not expose such application outside of a VPN, which is a blanket security practice that most selhosters should do for most of their services…