Probably it’s civil law/tort law, not criminal law. Like, someone can’t go to jail for it, but can be sued over it.

Crimes are only violations of criminal law.

googles

https://en.wikipedia.org/wiki/Trespass_in_English_law

Trespass in English law is an area of tort law broadly divided into three groups: trespass to the person, trespass to goods, and trespass to land.

Sounds like that might be the case.

Trespass in English (and Welsh) law is mostly a civil tort rather than a criminal offence. The circumstances in which it is a criminal offence are usually trespass on educational premises, railway property, protected sites, etc.[failed verification]

Not the case here in the States:

https://en.wikipedia.org/wiki/Trespass_to_land

United States

In most states, a criminal trespass to land is defined by statute and constitutes a misdemeanor. In some states, it may be a felony under certain circumstances (e.g., trespassing on a research facility or school property). Remedies between private parties for trespass may include an injunction or money damages.

These are old laws, and maybe good ones depending on perspective. My understanding is that property should be used if abandoned.