Or the worms that scan for vulnerable services and install persistent threats.
If you want to remove the password on a service, that’s your choice. The default should have a password though and then people can decide.
Defense in depth is essential in an age of unreliable software supply chain.
I don't think it's sensible to expect every project like Ollama to ship their own half-broken authentication and especially anything resembling a "zero trust" implementation. You can easily front Ollama with a reverse proxy which does those things if you'd like. Each component should do one thing well.
I trust Nginx to verify client certificates correctly so I can be confident that only traffic from trusted users is able to reach whatever insecure POS is hiding behind it.
Even if those services had some access protection, I simply must assume that the service has some security leak that allows unauthorized access and the first line of defense against that is not having it on the public internet.