>"you're responsible for securing your own property, security guards are a thing everywhere."
Maybe Bulgaria differs from most countries, but security guards seem to be mostly theatre. Private actors are generally very limited in what they can do to secure property, and they're usually required to basically call the police and hope the police show up in time to do something, which is often unlikely in either the countryside or industrial areas.
In Bulgaria the security guards used to be just protection rackets. Then EU happened and the country normalized but even the previous prime minister used to be a bodyguard.
When those people aren’t around Bulgaria is incredibly peaceful country.
Security, physical or software is multi-tiered.
You install gates, raise walls, limit access, hire personnel, etc.
The more you need to secure whatever it is, the more layers you have.
In general, any respectable warehouse would have an external wall with a single entrance to the parking, and then a second entrance to the building itself.
It really depends on the site being secured and who's acting as a guard. Try to storm a major US airbase and you'll learn very quickly that not all guards are created equal. Do the same as your local strip mall and yeah... that guy is only there to break up fights between kids and call the cops.
I think the point would be that it's the private company's responsibility to provide a minimum level of security, even if their job is just for deterrence, documentation, and notifying police in a timely manner. Even if it's mostly "theatre" it still serves a purpose.