In the case of the irrigation road, since from another post of yours upthread it appears to be private property, it should be signed accordingly to make it clear to people that they are trespassing if they use it.
Yes, it would be nice if Google would take steps to ensure the accuracy of maps and make guarantees accordingly, but it doesn't (and I don't see how it ever will unless and until maps becomes a paid application instead of a free one).
There could be jurisdictions that disagree with this. The US delegates quite a lot to contract law, but say Germany (I’m not sure if they do, but it sounds like it could be a German thing) could definitely decide that the act of providing a map with navigational assistance is sufficient to make some legal guarantees about accuracy.
Also, Google is currently being sued for a situation exactly like this so we will know soon enough if that defense works: https://arstechnica.com/tech-policy/2023/09/lawsuit-says-man...
Basically the last resort is to create a thread on Google Community Guide forums, then actual staff will eventually address the issue.
But is tedious and ridiculous how there's so little recourse against Google spreading incorrect info.